Which pedigree symbol is used to represent a female carrier of a recessive X-linked trait?

A half-shaded square.

Explanation:

Squares represent females, and since she is a carrier, the square is half-shaded, if it was fully shaded, she would be affected.

c. movement because i took the test and it lets me review my answers

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.