Answer:
Flourishing of trade
Step-by-step explanation:
The West and East Africa saw several societies develop within the same geographic areas because of the availability of natural resources which they traded with one another. African city-states and empires gained wealth through developing and trading resources. The empires flourished in West Africa were Ghana, Mali, and Songhai. The gold and salt played a role in the rise of trade in the region.
Villages along the east coast began with fishing and farming which later develop into trade cities with bustling seaports. The cities on the east coast were flourishing because of trade through the Indian Ocean with India, Arabia, Persia, and Rome.