You will be given a definition of a task first, then some input of the task.
In this task, you are given a context, a subject, a relation, and many options. Based on the context, from the options select the object entity that has the given relation with the subject. Answer with text (not indexes).

Context: Central Africa is a core region of the African continent which includes Burundi, the Central African Republic, Chad, the Democratic Republic of the Congo, and Rwanda. Middle Africa (as used by the United Nations when categorising geographic subregions) is an analogous term that includes Angola, Cameroon, the Central African Republic, Chad, the Republic of the Congo, the Democratic Republic of the Congo, Equatorial Guinea, Gabon, and São Tomé and Príncipe. All of the states in the UN subregion of Middle Africa, plus those otherwise commonly reckoned in Central Africa (11 states in total), constitute the Economic Community of Central African States (ECCAS). Since its independence in 2011, South Sudan has also been commonly included in the region., The Central African Republic (CAR; Sango: "Ködörösêse tî Bêafrîka";   , or "" ) is a landlocked country in Central Africa. It is bordered by Chad to the north, Sudan to the northeast, South Sudan to the east, the Democratic Republic of the Congo and the Republic of the Congo to the southwest and Cameroon to the west. The CAR covers a land area of about and had an estimated population of around 4.7 million ., Sudan ("as-Sdn", ), also known as North Sudan and officially the Republic of the Sudan ("Jumhriyyat as-Sdn"), is a country in Northern Africa. It is bordered by Egypt to the north, the Red Sea, Eritrea, and Ethiopia to the east, South Sudan to the south, the Central African Republic to the southwest, Chad to the west and Libya to the northwest. It is the third largest country in Africa. The River Nile divides the country into eastern and western halves. Before the Sudanese Civil War, South Sudan was part of Sudan but broke away in 2011. Its predominant religion is Islam., Arabic (' or ' ) is a Central Semitic language that was first spoken in Iron Age northwestern Arabia and is now the "lingua franca" of the Arab world. Arabic also is a liturgical language of 1.7 billion Muslims. It is one of six official languages of the United Nations. It is named after the Arabs, a term initially used to describe peoples living from Mesopotamia in the east to the Anti-Lebanon mountains in the west, and from northwestern Arabia to the Sinai in the south., Cameroon, officially the Republic of Cameroon, is a country in Central Africa. It is bordered by Nigeria to the west; Chad to the northeast; the Central African Republic to the east; and Equatorial Guinea, Gabon, and the Republic of the Congo to the south. Cameroon's coastline lies on the Bight of Bonny, part of the Gulf of Guinea and the Atlantic Ocean., Mandoul Oriental is one of three departments in Mandoul, a region of Chad. Its capital is Koumra., A landlocked state or landlocked country is a sovereign state entirely enclosed by land, or whose only coastlines lie on closed seas. There are currently 48 such countries, including four partially recognised states. Only two, Bolivia and Paraguay in South America, lie outside Afro-Eurasia (the Old World)., Koumra (Arabic: , "Qumra") is a town in southern Chad. It is the capital of the region of Mandoul and of the department of Mandoul Oriental. It is the sixth largest town in Chad., The Federal Republic of Nigeria , commonly referred to as Nigeria, is a federal republic in West Africa, bordering Benin in the west, Chad and Cameroon in the east, and Niger in the north. Its coast in the south lies on the Gulf of Guinea in the Atlantic Ocean. It comprises 36 states and the Federal Capital Territory, where the capital, Abuja is located. Its largest cities include: Lagos, Kano, Ibadan, Benin City and Port Harcourt. Nigeria is officially a democratic secular country., Chad ('), officially the Republic of Chad ('), is a landlocked country in Central Africa. It is bordered by Libya to the north, Sudan to the east, the Central African Republic to the south, Cameroon and Nigeria to the southwest and Niger to the west. It is the fifth largest country in Africa in terms of area., Libya ("") is a country in the Maghreb region of North Africa, bordered by the Mediterranean Sea to the north, Egypt to the east, Sudan to the southeast, Chad and Niger to the south, and Algeria and Tunisia to the west. The three traditional parts of the country are Tripolitania, Fezzan and Cyrenaica. With an area of almost , Libya is the fourth largest country in Africa, and is the 16th largest country in the world. Libya has the 10th-largest proven oil reserves of any country in the world., Niger (or ), officially the Republic of Niger, is a landlocked country in Western Africa, named after the Niger River. Niger is bordered by Libya to the northeast, Chad to the east, Nigeria and Benin to the south, Burkina Faso and Mali to the west, and Algeria to the northwest. Niger covers a land area of almost 1,270,000 km, making it the largest country in West Africa, with over 80 percent of its land area covered by the Sahara Desert. The country's predominantly Islamic population of about 19 million is mostly clustered in the far south and west of the country. The capital city is Niamey, located in the far-southwest corner of Niger., Mandoul is one of the 22 regions of Chad . Located in the south of the country , it corresponds with part of the former prefecture of Moyen - Chari . The regional capital is Koumra . The main products are subsistence agriculture and cotton ., Subject: mandoul region, Relation: instance_of, Options: (A) 1 (B) age (C) area (D) capital (E) coast (F) community (G) continent (H) country (I) department (J) federal capital (K) federal republic (L) four (M) islam (N) language (O) ocean (P) official (Q) oil (R) part (S) region (T) region of chad (U) republic (V) river (W) sovereign state (X) state (Y) three (Z) town ([) two (\) war
Output:
region of chad