Which is true about mutations? A. They are always beneficial

B. They are always harmful

C. They are mostly neutral and unnoticed

D. They are always either beneficial or harmful

I think (D) its very rare and not beneficial very often

Explanation:

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.