The correct answer is (b), the Benguela current.
The Benguela current is a cold, northward-flowing ocean current that forms along the western coast of southern Africa. It is part of the South Atlantic Gyre, and is a major factor in the climate of the region. The Benguela current is responsible for upwelling of cold, nutrient-rich water from the deep ocean, which supports a large marine ecosystem. The current also plays a role in the formation of fog and clouds along the coast.
The Canary current is a warm, northward-flowing ocean current that forms along the western coast of Africa. It is part of the North Atlantic Gyre, and is a major factor in the climate of the region. The Canary current is responsible for the warm climate of the Canary Islands, and also plays a role in the formation of the Sahara Desert.
The Agulhas current is a warm, eastward-flowing ocean current that forms along the southern coast of Africa. It is part of the Indian Ocean Gyre, and is a major factor in the climate of the region. The Agulhas current is responsible for the warm climate of the Cape of Good Hope, and also plays a role in the formation of the Benguela current.
The Brazil current is a warm, southward-flowing ocean current that forms along the eastern coast of South America. It is part of the South Atlantic Gyre, and is a major factor in the climate of the region. The Brazil current is responsible for the warm climate of the Brazilian coast, and also plays a role in the formation of the Falkland current.