Please answer the following question: Information:  - The Great Belt,, is a strait between the major islands of Zealand ("Sjælland") and Funen ("Fyn") in Denmark. It is one of the three Danish Straits.  - Scandinavia is a historical and cultural region in Northern Europe characterized by a common ethnocultural North Germanic heritage and mutually intelligible North Germanic languages.  - Finland , officially the Republic of Finland, is a sovereign state in Northern Europe. A peninsula with the Gulf of Finland to the south and the Gulf of Bothnia to the west, the country has land borders with Sweden to the northwest, Norway to the north, and Russia to the east. Estonia is south of the country across the Gulf of Finland. Finland is a Nordic country situated in the geographical region of Fennoscandia, which also includes Scandinavia. Finland's population is 5.5 million (2014), staying roughly on the same level over the past two decades. The majority of the population is concentrated in the southern region. In terms of area, it is the eighth largest country in Europe and the most sparsely populated country in the European Union.  - Riga is the capital and the largest city of Latvia. With 696,593 inhabitants (2015), Riga is the largest city of the Baltic states and home to one third of Latvia's population. The city lies on the Gulf of Riga, at the mouth of the Daugava. Riga's territory covers and lies between above sea level, on a flat and sandy plain.  - The Gulf of Bothnia is the northernmost arm of the Baltic Sea. It is situated between Finland's west coast and Sweden's east coast. In the south of the gulf lie the Åland Islands, between the Sea of Åland and the Archipelago Sea.  - The Gulf of Riga, Bay of Riga, or Gulf of Livonia is a bay of the Baltic Sea between Latvia and Estonia.  - Allirahu is a large rock in Estonia , Baltic Sea . Its coordinates are 58 ° 17  57.87 `` N 22 ° 58  11.01 '' E.  - The North European Plain (or ), or Middle European Plain is a geomorphological region in Europe, mostly in Poland, Denmark, Germany, Belgium, the Netherlands (Low Countries), and a small part of northern France.  - The Baltic Sea (  ; ) is a sea of the Atlantic Ocean, enclosed by Scandinavia, Finland, the Baltic countries, and the North European Plain. It includes the Gulf of Bothnia, the Bay of Bothnia, the Gulf of Finland, the Gulf of Riga, and the Bay of Gdask. The sea stretches from 53°N to 66°N latitude and from 10°E to 30°E longitude. A mediterranean sea of the Atlantic, with limited water exchange between the two bodies, the Baltic Sea drains through the Danish islands into the Kattegat by way of the straits of Øresund, the Great Belt, and the Little Belt.  - The Kattegat or Kattegatt is a sea area bounded by the Jutlandic peninsula in the west, the Danish straits islands of Denmark to the south and the provinces of Västergötland, Scania, Halland and Bohuslän in Sweden in the east. The Baltic Sea drains into the Kattegat through the Danish Straits. The sea area is a continuation of the Skagerrak and may be seen as a bay of the Baltic Sea or the North Sea or, as in traditional Scandinavian usage, neither of these.  - In geography, latitude is a geographic coordinate that specifies the northsouth position of a point on the Earth's surface. Latitude is an angle (defined below) which ranges from 0° at the Equator to 90° (North or South) at the poles. Lines of constant latitude, or parallels, run eastwest as circles parallel to the equator. Latitude is used together with longitude to specify the precise location of features on the surface of the Earth. Approximations employed. Two levels of abstraction are employed in the definition of these coordinates. In the first step the physical surface is modelled by the geoid, a surface which approximates the mean sea level over the oceans and its continuation under the land masses. The second step is to approximate the geoid by a mathematically simpler reference surface. The simplest choice for the reference surface is a sphere, but the geoid is more accurately modelled by an ellipsoid. The definitions of latitude and longitude on such reference surfaces are detailed in the following sections. Lines of constant latitude and longitude together constitute a graticule on the reference surface. The latitude of a point on the "actual" surface is that of the corresponding point on the reference surface, the correspondence being along the normal to the reference surface which passes through the point on the physical surface. Latitude and longitude together with some specification of height constitute a geographic coordinate system as defined in the specification of the ISO 19111 standard.  - The Gulf of Finland  is the easternmost arm of the Baltic Sea. It extends between Finland (to the north) and Estonia (to the south) all the way to Saint Petersburg in Russia, where the river Neva drains into it. Other major cities around the gulf include Helsinki and Tallinn. The eastern parts of the Gulf of Finland belong to Russia, and some of Russia's most important oil harbours are located farthest in, near Saint Petersburg (including Primorsk). As the seaway to Saint Petersburg, the Gulf of Finland has been and continues to be of considerable strategic importance to Russia. Some of the environmental problems affecting the Baltic Sea are at their most pronounced in the shallow gulf.  - Øresund or Öresund is a strait which forms the DanishSwedish border, separating Sjælland (Denmark) from Skåne (Sweden).  The strait has a length of and the width varies from to . It is wide at its narrowest point between Helsingør in Denmark and Helsingborg in Sweden.   - The Atlantic Ocean is the second largest of the world's oceans with a total area of about . It covers approximately 20 percent of the Earth's surface and about 29 percent of its water surface area. It separates the "Old World" from the "New World".  - Water is a transparent and nearly colorless chemical substance that is the main constituent of Earth's streams, lakes, and oceans, and the fluids of most living organisms. Its chemical formula is HO, meaning that its molecule contains one oxygen and two hydrogen atoms, that are connected by covalent bonds. Water strictly refers to the liquid state of that substance, that prevails at standard ambient temperature and pressure; but it often refers also to its solid state (ice) or its gaseous state (steam or water vapor). It also occurs in nature as snow, glaciers, ice packs and icebergs, clouds, fog, dew, aquifers, and atmospheric humidity.  - Longitude (or , Australian and British also ), is a geographic coordinate that specifies the east-west position of a point on the Earth's surface. It is an angular measurement, usually expressed in degrees and denoted by the Greek letter lambda (). Meridians (lines running from the North Pole to the South Pole) connect points with the same longitude. By convention, one of these, the Prime Meridian, which passes through the Royal Observatory, Greenwich, England, was allocated the position of zero degrees longitude. The longitude of other places is measured as the angle east or west from the Prime Meridian, ranging from 0° at the Prime Meridian to +180° eastward and 180° westward. Specifically, it is the angle between a plane containing the Prime Meridian and a plane containing the North Pole, South Pole and the location in question. (This forms a right-handed coordinate system with the axis (right hand thumb) pointing from the Earth's center toward the North Pole and the axis (right hand index finger) extending from Earth's center through the equator at the Prime Meridian.)  - A sea is a large body of salt water that is surrounded in whole or in part by land. More broadly, "the sea" is the interconnected system of Earth's salty, oceanic watersconsidered as one global ocean or as several principal oceanic divisions. The sea moderates Earth's climate and has important roles in the water cycle, carbon cycle, and nitrogen cycle. Although the sea has been traveled and explored since prehistory, the modern scientific study of the seaoceanographydates broadly to the British "Challenger" expedition of the 1870s. The sea is conventionally divided into up to five large oceanic sectionsincluding the International Hydrographic Organization's four named oceans (the Atlantic, Pacific, Indian, and Arctic) and the Southern Ocean; smaller, second-order sections, such as the Mediterranean, are known as "seas".  - The Little Belt is a strait between the island of Funen and the Jutland Peninsula in Denmark. It is one of the three Danish Straits that drain and connect the Baltic Sea to the Kattegat strait, which drains west to the North Sea and Atlantic Ocean.  - Gdask (German: ) is a Polish city on the Baltic coast. It is the capital of the Pomeranian Voivodeship, Poland's principal seaport and is also the centre of the country's fourth-largest metropolitan area.    After reading the paragraphs above, we are interested in knowing the entity with which 'allirahu' exhibits the relationship of 'instance of'. Find the answer from the choices below.  Choices: - abstraction  - angle  - bay  - belt  - border  - capital  - chemical  - city  - climate  - coast  - country  - cycle  - england  - exchange  - five  - formula  - geographical  - geography  - gulf  - hydrogen  - index  - island  - liquid  - location  - may  - meridian  - molecule  - observatory  - ocean  - order  - plain  - point  - population  - position  - prime meridian  - reference  - region  - republic  - river  - running  - saint  - salt  - sea  - seaport  - snow  - sovereign state  - sphere  - strait  - study  - surface  - system  - three  - two  - vapor  - water
A:
island