Please answer the following question: Information:  - The Siege of Tkvarcheli refers to the eventually unsuccessful siege of the Abkhazian town of Tkvarcheli during the 1992 -- 93 War in Abkhazia by the National Guard of Georgia . The siege lasted from October 1992 to September 1993 , covering almost the entire duration of the war . It was accompanied by inconclusive fighting in surrounding villages . Russian aid , both humanitarian and military , was critical for the defence of the town which suffered a severe humanitarian crisis during the siege .  - The Black Sea is a body of water between Eastern Europe and Western Asia, bounded by Bulgaria, Georgia, Romania, Russia, Turkey, and Ukraine. It is supplied by a number of major rivers, such as the Danube, Dnieper, Rioni, Southern Bug, and Dniester. The Black Sea has an area of (not including the Sea of Azov), a maximum depth of , and a volume of . It is constrained by the Pontic Mountains to the south and by the Caucasus Mountains to the east, and features a wide shelf to the northwest. The longest east-west extent is about .  - Sukhumi or Sokhumi ("Aqwa"  "Sukhum(i)") is a city on the Black Sea coast. It is the capital of the breakaway Republic of Abkhazia which has controlled it since the 1992-93 war in Abkhazia, although most of the international community considers it legally part of Georgia.  - Ochamchire or Ochamchira ( "Ochamchyra" "Ochamchira") is a seaside city on the Black Sea coast of Abkhazia, Georgia. and a centre of the eponymous district.  - A humanitarian crisis (or "humanitarian disaster") is defined as a singular event or a series of events that are threatening in terms of health, safety or well being of a community or large group of people. It may be an internal or external conflict and usually occurs throughout a large land area. Local, national and international responses are necessary in such events.  - The Caucasus Mountains are a mountain system in Eurasia between the Black Sea and the Caspian Sea in the Caucasus region.  - The Georgian Armed Forces is the name of the unified armed forces of Georgia. The Georgian military is a defence force consisting of the Georgian Land Forces, Georgian Special Forces and a paramilitary organization, the Georgian National Guard. The national defense policy aims, based on the Constitution of Georgia, are to guarantee the preservation of the independence and sovereignty of the state and the integrity of its land area, territorial waters and airspace and its constitutional order. The armed forces of Georgia are under the authority of the Georgian Ministry of Defense. The Georgian Armed Forces is not to be confused with the American Civil War army known as the Army of Georgia  - Tkvarcheli ( "Tqwarchal" "Tkvarcheli") is a town in Abkhazia, Georgia. It is situated on the river Ghalidzga (Aaldzga) and a railroad connects it with Ochamchire.  - Abkhazia (' ; ' ) is a partially recognised state on the eastern coast of the Black Sea and the south-western flank of the Caucasus Mountains, south of Russia and northwest of Georgia proper. It covers and has a population of around 240,000. Its capital is Sukhumi. The separatist Abkhazian polity, formally the Republic of Abkhazia or Apsny, is recognised only by Russia and a small number of other countries. While Georgia lacks control over Abkhazia, the Georgian government, the United Nations and the majority of the world's governments consider Abkhazia part of Georgia, whose constitution designates the area the Autonomous Republic of Abkhazia.  - Russia (from the  Rus'), also officially known as the Russian Federation, is a country in Eurasia. At , Russia is the largest country in the world by surface area, covering more than one-eighth of the Earth's inhabited land area, and the ninth most populous, with over 140 million people at the end of March 2016. The European western part of the country is much more populated and urbanised than the eastern, about 77% of the population live in European Russia. Russia's capital Moscow is one of the largest cities in the world, other major urban centers include Saint Petersburg, Novosibirsk, Yekaterinburg, Nizhny Novgorod and Samara.  - The United Nations (UN) is an intergovernmental organization to promote international co-operation. A replacement for the ineffective League of Nations, the organization was established on 24 October 1945 after World War II in order to prevent another such conflict. At its founding, the UN had 51 member states; there are now 193. The headquarters of the United Nations is in Manhattan, New York City, and experiences extraterritoriality. Further main offices are situated in Geneva, Nairobi, and Vienna. The organization is financed by assessed and voluntary contributions from its member states. Its objectives include maintaining international peace and security, promoting human rights, fostering social and economic development, protecting the environment, and providing humanitarian aid in cases of famine, natural disaster, and armed conflict.  - The National Guard of Georgia (NG) ("sak'art'velos erovnuli gvardia") is a military structure within the Georgian Armed Forces and has a department status within the Ministry of Defense. It is tasked with responding to external threats, civil disturbances, and natural disasters. The GNG is also responsible for the mobilization of reservists.    After reading the paragraphs above, we are interested in knowing the entity with which 'siege of tkvarcheli' exhibits the relationship of 'instance of'. Find the answer from the choices below.  Choices: - area  - armed conflict  - armed forces  - army  - art  - body of water  - capital  - city  - civil war  - community  - conflict  - constitution  - country  - crisis  - department  - disaster  - event  - federation  - force  - government  - headquarters  - health  - league  - march  - may  - member  - military  - ministry  - mountain  - name  - october  - operation  - order  - organization  - part  - people  - population  - preservation  - rights  - river  - sea  - special forces  - state  - status  - system  - town  - war
A:
conflict