Trade among west African countries is less developed mainly because

• A.they were ruled by different colonial powers which created a barrier to communication
• B.the products of one country are basically similar to those of the others
• C.there are no international railway lines to transport the bulky items of trade across the borders
• D.of ethnic sentiments of people in one country against the other
• E.no west African country has surpluses of commodities to export to the other countries