What are limiting factors for plant growth

Conversely, the lack of water has always been a determinant factor preventing not only plant growth, but also plant life. There are in general four primary factors affecting plant growth, sunlight, water, temperature and nutrients, including CO2, nitrogen, phosphorus and others

I hope this helps!

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.

helicase, i think thats it