Which kind of environmental change would a tomado be? short-term, because it occurs very quickly
O long-term, because it lasts a long time
O short-term, because it affects only a small area
O long-term, because they have been happening for millions of years

Short term

Explanation:

Because it occurs very quickly

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.