With Regard to the Rulers of the West African Coastal

With regard to the rulers of the West African coastal states of Dahomey and Asante, which of the following statements accurately describes their role in the slave trade and the trade's impact on them?

A) Although they controlled aspects of the slave trade, the coastal kings were merely the puppets of European traders who controlled them and the territory they governed.
B) By centralizing and controlling the slave trade, the kings of these states oversaw the emergence of powerful kingdoms.
C) Since the Europeans completely controlled the slave trade, the coastal kings were merely figureheads with no real power.
D) Although the coastal kings allowed the Europeans to control the slave trade, they acquired power and wealth by gaining control over the trans-Saharan trade.