How did the cities develop as a result of trees in Africa?
a. along the coast of Africa, trading cities, such as aksum, developed, allowing traders to move easily take a vantage of trade routes that connected to southwest Asia ( the arabian peninsula )
b. cities on the Niger River, such as Djenne and Timbuktu, became centers of trade as they were at the center of the exchange of natural resources, such as salt from the Sahara and gold mines in the forests
c. The city of great Zimbabwe developed due to its proximity to a specific natural resource, gold
d. all of the above