What conclusion can be made from the data in the graph? 0 Transpiration does not occur in the dark
O Stomata open as temperature decreases.
O Stomata open as light intensity increases.
O Gas exchange occurs when stomata are open.

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."

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.

i believe your answer would be c.. : )