Answer:
Correct Answer is: Savanna
Step-by-step explanation:
Subsaharan Africa is the region below the Sahara desert, this region has a wide variety of biomes and ecoregions filling the landscape, from savannas like Serengeti in the east and tropical forest in the center, the Nile river forming this enormous Basin.
For human inhabitations there is a need on natural resources like water, Nile basin and tropical forest are perhaps the ideals for a civilization, and the savannas with long extensions of grasslands is definitely where humans would have it harder to find resources, regarding savannas in Subsaharan africa, an important ecoregion is the Sahel, which is the transition between the Sahara and the Sudanian savanna and because of its temperature and big extensions with not much water is probably not heavily inhabited compared to the ideal conditions near the Nile river, an ecoregion that is known for being heavily populated.