Context: 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"., Gabon, officially the Gabonese Republic, is a sovereign state on the west coast of Central Africa. Located on the equator, Gabon is bordered by Equatorial Guinea to the northwest, Cameroon to the north, the Republic of the Congo on the east and south, and the Gulf of Guinea to the west. It has an area of nearly and its population is estimated at 1.5 million people. Its capital and largest city is Libreville., 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., Douala is the largest city in Cameroon, and the capital of Cameroon's Littoral Region. Home to Central Africa's largest port and its major international airport, Douala International Airport, it is the commercial and economic capital of Cameroon and the entire CEMAC region comprising Gabon, Congo, Chad, Equatorial Guinea, CAR and Cameroon. Consequently, it handles most of the country's major exports, such as oil, cocoa and coffee, timber, metals and fruits. the city and its surrounding area had an estimated population that surpassed 3,000,000 inhabitants. The city sits on the estuary of the Wouri River and its climate is tropical., Yabassi is a town and commune in western Cameroon, and capital of the Nkam department. Its population in 2001 was estimated at 12,000. The main dialect spoken is the Yabassi. However, there are also other dialects originating in the Nkam which are spoken., Cape Lopez is a 55 km-long peninsula on the coast of west central Africa, in the country of Gabon. It separates the Gulf of Guinea from the South Atlantic Ocean,, The Wouri ( also Vouri or Vuri ) is a river in Cameroon . The river is formed at the confluence of the rivers Nkam and Makombé , 32 km ( 20 mi ) northeast of the city of Yabassi . The Wouri then flows about 160 km ( 99 mi ) southeast to the Wouri estuary at Douala , the chief port and industrial city in the southwestern part of Cameroon on the Gulf of Guinea . The river is navigable about 64 km ( 40 mi ) upriver from Douala ., Cape Three Points is a small peninsula in the Western Region of Ghana on the Atlantic Ocean., 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 Guinea is the northeasternmost part of the tropical Atlantic Ocean between Cape Lopez in Gabon, north and west to Cape Three Points in Western region Ghana. The intersection of the Equator and Prime Meridian (zero degrees latitude and longitude) is in the gulf., The Republic of the Congo, also known as the Congo Republic, West Congo, Congo-Brazzaville or simply Congo, is a country located in Central Africa. It is bordered by five countries: Gabon and the Atlantic Ocean to the west; Cameroon to the northwest; the Central African Republic to the northeast; the Democratic Republic of the Congo to the east and south; and the Angolan exclave of Cabinda to the southwest., Ghana, officially the Republic of Ghana is a unitary presidential constitutional democracy, located along the Gulf of Guinea and Atlantic Ocean, in the subregion of West Africa. Spanning a land mass of 238,535 km², Ghana is bordered by the Ivory Coast in the west, Burkina Faso in the north, Togo in the east and the Gulf of Guinea and Atlantic Ocean in the south. "Ghana" means "Warrior King" in the Soninke language., 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., Coffee is a brewed drink prepared from roasted coffee beans, which are the seeds of berries from the "Coffea" plant. The genus Coffea is native to tropical Africa, and Madagascar, the Comoros, Mauritius and Réunion in the Indian Ocean. The plant was exported from Africa to countries around the world and coffee plants are now cultivated in over 70 countries, primarily in the equatorial regions of the Americas, Southeast Asia, India, and Africa. The two most commonly grown are the highly regarded arabica, and the less sophisticated but stronger and more hardy robusta. Once ripe, coffee berries are picked, processed, and dried. Dried coffee seeds (referred to as beans) are roasted to varying degrees, depending on the desired flavor. Roasted beans are ground and brewed with near boiling water to produce coffee as a beverage., Equatorial Guinea, officially the Republic of Equatorial Guinea, is a country located in Central Africa, with an area of . Formerly the colony of Spanish Guinea, its post-independence name evokes its location near both the Equator and the Gulf of Guinea. Equatorial Guinea is the only sovereign African state in which Spanish is an official language. , the country has an estimated population of over 1.2 million., Subject: wouri river, Relation: mouth_of_the_watercourse, Options: (A) atlantic ocean (B) bight of bonny (C) gulf of guinea (D) indian ocean (E) main (F) sea
Output: bight of bonny