Concept:British West Africa's first elective legislative council seats for Africans were introduced in Nigeria.Explanation:In 1923, the Clifford Constitution established the first elective principle in British West Africa.This allowed Nigerians to vote for African members of the legislative council.No other British West African colony had such elected African representatives at that time.Thus, Nigeria was the first territory where Africans were elected to the legislative council.Answer:D. Nigeria