Mansa Musa established Mali as a center of Muslim culture primarily through c. he brought Muslim scholars, artists, and teachers to work in Mali. His famous pilgrimage to Mecca (hajj) in 1324 showcased his wealth and commitment to Islam, and upon his return, he fostered an environment that attracted scholars and intellectuals. This led to the establishment of educational institutions and the flourishing of arts and culture in Mali, particularly in cities like Timbuktu and Gao, making them significant centers of learning and Islamic culture.
While the other options have elements of truth regarding his impact on trade and territory, the focal point of his contribution to Mali as a center of Muslim culture is best captured by choice c.