The best answer is C.
The dust bowl was the name that was given to the Great Plains region of America following the great dust storms of the 1930s.
One of the major factors that led to this was poor agricultural practices that depleted the top soil so much that it lacked the strong root system of grass as an anchor and became loose.
The winds easily picked up the loose top soil and swirled it into dense dust clouds, also named black blizzards, which caused much havoc in the land by chocking cattle and pasture land, driving 60% of the population from the region.
