Why do most people live in the sahara?

"Actually, not a lot of people live in the Sahara itself. People live along the Nile river, especially in the delta area, because that area is very fertile and has supported human habitation for thousands of years. Also, people live along the Mediterranean coast and in coastal mountain (which are not desert) because those areas also support agriculture, fishing, and animal husbandry. 

Those people who are referred to as "nomads" are generally traders who cross the Sahara with goods to trade. They are not the same as nomadic herders. 

In general, people live where their ancestors lived. Only wealthy people in developed nations can afford to choose their location based on personal preference."

Dall of the above all of the choices make sense

Iwould say d. eye contact and body language because you aren’t using any spoken communication. hope this : )