Crickets go through a form, in which they resemble the parent when hatched but develop other features like wings later on.
nymph
pupa
larva

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.

option c is the correct answer.