Answer:
Islam
Step-by-step explanation:
Islam was most popular religion in the commercial centers of West Africa and the Swahili city-states of East Africa. In the sixteenth century the trading city of Timbuktu had a prominent university for this religion.
The city of Timbuktu was a large commercial area and the Islamic language was instrumental in trade between cities in the region. This is what led to a vast propagation of the religion in the city.