Which process of soil erosion is being prevented by the structure shown below?
select one:
a. wind
b. gravity
c. glaciers
d. moving water

I believe the answer is A. Wind
That structure will act as some sort of barrier that wil block the wind which come towards the plant.
Placing that structure on top of the plant will  reduce the speed of incoming wind, and prevent the force from creating a destruction of the land composition.