Which of the following international organizations did all West African countries belong to?

A.

Organization of Petroleum Exporting Countries

B.

North Atlantic Treaty Organization

C.

European Union

D.

Organization of African Unity

Correct answer is D

Organization of African Unity (OAU) . Founded in 1963, it aims to safeguard the interests and independence of all African states, encourage the continent's development, and settle disputes among member states. Its headquarters are in Addis Ababa, Ethiopia. All west African states were members of the organisation form its inception