The correct answer is B) over-farming.
One of the chief causes of the environmental conditions shown on this map is over-farming.
Over-farming in Africa is causing desertification. As seen in the attached map of Africa, many African territories are at risk of desertification. Some more than others, but the risk is present.
Desertification occurs when fertile land becomes desert. It is caused by human activities that degraded the land such as over-cultivation, deforestation, and overgrazing. Weather conditions such as drought is also a factor that produces desertification.
