I need help with #3 bad please i’ll give u a brainliest if u give me the correct answer i promise

Its A

Explanation:

If you look closeley at the modle you can start to notice a pattern. Therefore a repeating structure. And they arent moving freely since they are combined into a compound to create NaCi.

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.

a. to encourage apoptosis