Please answer the following question: Information:  - A port is a location on a coast or shore containing one or more harbors where ships can dock and transfer people or cargo to or from land. Port locations are selected to optimize access to land and navigable water, for commercial demand, and for shelter from wind and waves. Ports with deeper water are rarer, but can handle larger ships. Since ports throughout history handled every kind of traffic, support and storage facilities vary widely, may extend for miles, and dominate the local economy. Some ports have an important military role.  - A photograph or photo is an image created by light falling on a light-sensitive surface, usually photographic film or an electronic medium such as a CCD or a CMOS chip. Most photographs are created using a camera, which uses a lens to focus the scene's visible wavelengths of light into a reproduction of what the human eye would see. The process and practice of creating photographs is called photography. The word "photograph" was coined in 1839 by Sir John Herschel and is based on the Greek  ("phos"), meaning "light", and  ("graphê"), meaning "drawing, writing", together meaning "drawing with light".  - The Roman Empire (Koine and Medieval Greek:   , tr. ) was the post-Roman Republic period of the ancient Roman civilization, characterized by government headed by emperors and large territorial holdings around the Mediterranean Sea in Europe, Africa and Asia. The city of Rome was the largest city in the world BC AD, with Constantinople (New Rome) becoming the largest around 500 AD, and the Empire's populace grew to an estimated 50 to 90 million inhabitants (roughly 20% of the world's population at the time). The 500-year-old republic which preceded it was severely destabilized in a series of civil wars and political conflict, during which Julius Caesar was appointed as perpetual dictator and then assassinated in 44 BC. Civil wars and executions continued, culminating in the victory of Octavian, Caesar's adopted son, over Mark Antony and Cleopatra at the Battle of Actium in 31 BC and the annexation of Egypt. Octavian's power was then unassailable and in 27 BC the Roman Senate formally granted him overarching power and the new title "Augustus", effectively marking the end of the Roman Republic.  - Graffiti (plural of "graffito": "a graffito", but "these graffiti") are writing or drawings that have been scribbled, scratched, or painted illicitly on a wall or other surface, often within public view. Graffiti range from simple written words to elaborate wall paintings, and they have existed since ancient times, with examples dating back to Ancient Egypt, Ancient Greece, and the Roman Empire.  - The Metropolitan Museum of Art, colloquially "the Met", is located in New York City and is the largest art museum in the United States, and is among the most visited art museums in the world. Its permanent collection contains over two million works, divided among seventeen curatorial departments. The main building, on the eastern edge of Central Park along Manhattan's Museum Mile, is by area one of the world's largest art galleries. A much smaller second location, The Cloisters at Fort Tryon Park in Upper Manhattan, contains an extensive collection of art, architecture, and artifacts from Medieval Europe. On March 18, 2016, the museum opened the Met Breuer museum at Madison Avenue in the Upper East Side; it extends the museum's modern and contemporary art program.  - Ancient Egypt was a civilization of ancient Northeastern Africa, concentrated along the lower reaches of the Nile River in what is now the modern country of Egypt. It is one of six civilizations to arise independently. Egyptian civilization followed prehistoric Egypt and coalesced around 3150 BC (according to conventional Egyptian chronology) with the political unification of Upper and Lower Egypt under the first pharaoh Narmer (commonly referred to as Menes). The history of ancient Egypt occurred in a series of stable kingdoms, separated by periods of relative instability known as Intermediate Periods: the Old Kingdom of the Early Bronze Age, the Middle Kingdom of the Middle Bronze Age and the New Kingdom of the Late Bronze Age.  - Henry Chalfant (born January 2, 1940 in Sewickley, Pennsylvania, United States) is an American photographer and videographer most notable for his work on graffiti, breakdance, and hip hop culture. His photos are in the collections of the Metropolitan Museum of Art in New York City, and the Carnegie Institute in Pittsburgh, Pennsylvania.  - Research comprises "creative work undertaken on a systematic basis in order to increase the stock of knowledge, including knowledge of humans, culture and society, and the use of this stock of knowledge to devise new applications." It is used to establish or confirm facts, reaffirm the results of previous work, solve new or existing problems, support theorems, or develop new theories. A research project may also be an expansion on past work in the field. Research projects can be used to develop further knowledge on a topic, or in the example of a school research project, they can be used to further a student's research prowess to prepare them for future jobs or reports. To test the validity of instruments, procedures, or experiments, research may replicate elements of prior projects or the project as a whole. The primary purposes of basic research (as opposed to applied research) are documentation, discovery, interpretation, or the research and development (R&D) of methods and systems for the advancement of human knowledge. Approaches to research depend on epistemologies, which vary considerably both within and between humanities and sciences. There are several forms of research: scientific, humanities, artistic, economic, social, business, marketing, practitioner research, life, technological,etc.  - The City of New York, often called New York City or simply New York, is the most populous city in the United States. With an estimated 2015 population of 8,550,405 distributed over a land area of just , New York City is also the most densely populated major city in the United States. Located at the southern tip of the state of New York, the city is the center of the New York metropolitan area, one of the most populous urban agglomerations in the world. A global power city, New York City exerts a significant impact upon commerce, finance, media, art, fashion, research, technology, education, and entertainment, its fast pace defining the term "New York minute". Home to the headquarters of the United Nations, New York is an important center for international diplomacy and has been described as the cultural and financial capital of the world.  - Subway Art is a collaborative book by Martha Cooper and Henry Chalfant , which documents the early history of New York City 's graffiti movement . Originally published in 1984 , the book has been described as a `` landmark photographic history '' and holds great significance in exporting graffiti and the wider hip hop culture internationally . The book features artists such as Zephyr , Seen , Kase2 , Dondi and Lady Pink . The 25th anniversary edition was released in 2009 , available in large print measuring 43x30.5 cm.  - In the study of human settlements, an urban agglomeration is an extended city or town area comprising the built-up area of a central place ("usually a municipality") and any suburbs linked by continuous urban area. INSEE, the French Statistical Institute, uses the term "unité urbaine", which means continuous urbanized area. However, because of differences in definitions of what does and does not constitute an "agglomeration", as well as variations and limitations in statistical or geographical methodology, it can be problematic to compare different agglomerations around the world. It may not be clear, for instance, whether an area should be considered to be a satellite and part of an agglomeration, or a distinct entity in itself.  - Martha Cooper is an American photojournalist born in the 1940s in Baltimore, Maryland. She worked as a staff photographer for the "New York Post" during the 1970s. She is best known for documenting the New York City graffiti scene of the 1970s and 1980s.  - Ancient Greece was a civilization belonging to a period of Greek history from the Greek Dark Ages of the 12th-9th centuries BC to the end of antiquity (AD). Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Roughly three centuries after the Late Bronze Age collapse of Mycenaean Greece, Greek urban poleis began to form in the 8th century BC, ushering in the period of Archaic Greece and colonization of the Mediterranean Basin. This was followed by the period of Classical Greece, an era that began with the Greco-Persian Wars, lasting from the 5th to 4th centuries BC. Due to the conquests by Alexander the Great of Macedonia, Hellenistic civilization flourished from Central Asia to the western end of the Mediterranean Sea. The Hellenistic period came to an end with the conquests and annexations of the eastern Mediterranean world by the Roman Republic, which established the Roman province of Macedonia in Roman Greece, and later the province of Achaea during the Roman Empire.  - Headquarters (HQ) denotes the location where most, if not all, of the important functions of an organization are coordinated. In the United States, the corporate headquarters represents the entity at the center or the top of a corporation taking full responsibility for managing all business activities. In the UK, the term head office is most commonly used for the HQs of large corporations. The term is also used regarding military organizations.    Given the information above, choose from the list below the object entity that exhibits the relation 'genre' with the subject 'subway art'.  Choices: - art  - breakdance  - contemporary art  - country  - education  - entertainment  - fashion  - finance  - government  - graffiti  - history  - image  - march  - marketing  - military  - persian  - photography  - research  - society  - study  - urban
A:
photography