Answer:
B
Explanation:
It is just process of elimination.
The text clearly states that fences were blown down in the second paragraph, it turned the farms into piles of sand in the third paragraph, and since this most likely represent the Great Depression and the Dust Bowl, fertile soil is blown away.
Fertile soil is usually near the top soil or a few feet down since water mostly accumulates there and gets soaked in. When there is extreme wind, the top soil and fertile soil gets blown away which just leaves dust.
