In the 15th and 16th centuries, three great powers arose in a band across western and southern Asia. The Ottoman, Safavid, and Mughal dynasties established control over Turkey, Iran, and India respectively, in large part due to a Chinese invention: gunpowder. ... As a result, they are called the "Gunpowder Empires."
The sahara trade took place in Africa, and Ghana is a main state in africa, B and C arent even located in Africa, so by process of elimination and background knowledge its D
