The Sahara is a hot desert yet people grow crops in some regions of this desert. What helps them to grow crops here?

To survive they have made modified leaves into spines to prevent excessive loss of water from the plant body and deep roots to get to a water source.

the answer is:

c. islam and christianity

explanation:

islam and christianity are widely practiced in africa. islam is practiced due to its spread from the middle east into africa, and christianity is practiced due to the colonization of africa by the british empire.