If you have a cell with more salt outside the cell, then inside the cell what will happen to the cell?

The cell would lose the water inside it causing it to die.

Explanation:

Water in cells moves towards the higher concentration of salt so if there is more on the outside the water would move on the outside causing it to die because it needs water. If it was the opposite and there was more salt inside more water would go inside causing the cell to swell and virtually exploding and diluting parts of our 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.