How did trade lead to the spread of culture in West Africa? As people interacted, they exchanged ideas, languages, and religions.
As people immigrated to West Africa, they traded with local villages.
As people met traders, they gained more wealth, influence, and power.
As people became wealthy, they used their influence to spread culture.

As people interacted, they exchanged ideas, languages, and religions.

Explanation:

Most merchants who come to trade to another region will most likely have to socialize with the local people there. During the socialization process, these merchants will talk about various topics ranging from their own culture, religion, knowledge, inventions, historical events, etc.

After the merchants came home, the local will spread the things that taught by the merchants to other locals. The merchant also will spread the things that the locals taught to his original country.  

true.

hope this !

i believe it was the shinto