Concept:Nigeria’s foreign policy has always placed Africa at the heart of its external relations.Explanation:Since independence in 1960, Nigeria focused on fighting colonialism, apartheid, and racial discrimination across Africa.It also promoted the liberation and unity of Black people on the continent.These actions reflect Afrocentrism, which makes African interests the center of foreign policy.Other options like sub-regionalism or globalism are narrower or broader, but Afrocentrism best captures Nigeria’s main focus.Answer:D. Afrocentrism