D because it seams most logical
well sahara is the largest hor desert of the world. the people became nomads, and goat and camel herders. The coatal area north of sahara does still produce fruits and some grains. Even durinf roman times the coastal area flourished with some powerful country/states, until the Romans conquered them and incoporated large areas of North Africa into the empire. if u will notice population in the sahara is not very large but is able to support certain tribes like the Tauregs.
..............hope it help!! >.<
