What are the historical names of the four stretches of coast from Liberia to Nigeria?

(A) Grain coast, Ivory coast, Gold coast and Slave coast
(B) Mountains coast, Free coast, Ivory coast and Niger Ivory coast
(C) Sierra Ivory coast, Ghana Ivory coast, Benin Ivory coast, Niger coast
(D) Palmas coast, Volta coast, Benin coast, Bonnen coast