When the temperature of its environment changes, the temperature of a snake

I think its B

Explanation:

a.

also changes.

b.

stays the same.

c.

increases.

d.

decreases.

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.