2. In plant and animal cells, the control center of the cell is the
a. chloroplast.
b. cytoplasm.
c. nucleus.
d. Golgi body.

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.