A major cause of depopulation in Nigeria in the 18th century was?

A. the trans-Atlantic slave trade
B. the trans-Saharan trade
C. human sacrifice
D. inter-ethnic warfare.

Correct Answer: Option A

A. the trans-Atlantic slave trade

Explanation

The Trans-Saharan Trade which had been on for many centuries included several articles of trade of which slaves were later added; the human sacrifice was only carried on a very small scale; interethnic warfare took place majorly in the nineteenth century.