It was difficult for the Nigerian coastal chiefs to give up the slave trade after its abolition because

A.

It had been part of African culture

B.

Africans were too involved to give up the trade

C.

The British Navy was not effective in enforcing the abolition

D.

The trade was still crucial to the economy of their states

Correct answer is D

The trade was very lucrative as participants made enormous revenue from it and were not ready to abandon it for any other type of trade the value of which they had not yet known.