How did the kings of Ghana become wealthy?

They mind salt from the region and sold it to neighboring regions
They controlled how much gold was available for trade
They use the Saharan trade, route to acquire, expensive ivory
They learn to make weapons from iron, and sold them to neighboring empires

The kings of Ghana became wealthy primarily through controlling the trade of gold in the region. They controlled how much gold was available for trade, enabling them to dictate prices and amass a significant amount of wealth. Additionally, they also mined and sold salt to neighboring regions, participated in the Saharan trade route to acquire expensive ivory, and learned to make weapons from iron which they sold to neighboring empires. Overall, their control over trade routes and valuable commodities allowed them to become incredibly wealthy and powerful.