A desert is very hot during the day and receives very little rain. Which plants have an adaptation that would help them survive?*

Well cacti for one

Explanation:

They can store water for a really long time because of the little rain.

the answer to you question is   jet streams

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.