The ancient Muslim historian Al-Omari described Mansa Musa as "the most powerful, the richest, the most fortunate, the most feared by his enemies and the most able to do good for those around him" in all of West Africa
How did Mansa Musa gain his fortune?

A) by forcing his subjects to convert to Islam
B) by resisting conquest by the Portuguese
C) by controlling the gold and salt trade
D) by conquering the city of Timbuktu