How was control of the gold and salt trade an important part of the rule of the Kingdoms of West Africa?

The people who lived in the desert of North Africa could easily mine salt, but not gold. … They craved the precious metal that would add so much to their personal splendor and prestige. These mutual needs led to the establishment of long-distance trade routes that connected very different cultures.

Ghana's rulers rose in power as gold and salt trade increased. They gradually developed armies of iron guns that were superior to the weapons of the natives. By 800, Ghana had established a strong grip on West Africa's trading routes. Ghana was the center for almost all trade between northern and southern Africa.

the answer for 3 is b and the answer for 4 is d