Which of the following factors contributed to the dust bowl

The Dust Bowl was the crisis that took place on the southern Great Plains in the North American Midwest and Canada during the 1930s. It was a period of drought and severe wind erosion in the southern and central plains, which was followed by economic depression. The northern parts of the Prairie were not affected as badly. The devastation of agriculture prolonged the Great Depression. It also led to great emigration. Poor farming practices helped to make the situation more difficult.

During the 1920s, many farmers moved to the plain, where new opportunities to increase production were seen. The grasslands were plowed up to grow grain. During years of abundant rainfall enough grain could be grown, but in the early 1930s a long and difficult drying period began. However, agriculture was run as before, which led to the soil becoming increasingly nutrient poor and the top layer that held the soil in place disappeared. A record crop of wheat in 1931 led to a fall in food prices and the farmers found it difficult to cope with their subsistence.

In 1931 the drought became even more difficult. The winds pulled particles from the ground and formed large dust clouds. Sandstorms became more and more common, and because there was no real vegetation that could bind soil and sand, huge dust clouds formed. In 1932, 14 sandstorms were reported, increasing to 38 in 1933. The sandstorms helped to make the situation worse; the particle content in the air increased to the extent that the sun's rays could not break through and the residents in the area experienced health problems. More and more people chose to leave the plain and the flight continued until 1941.

the correct answer is

d) rocket launcher