Base your answer to question on the passage below and on your knowledge of social studies. ... And then the dispossessed were drawn west -from Kansas, Oklahoma, Texas, New Mexico; from Nevada and Arkansas families, tribes, dusted out, traitored out. Carloads, caravans, homeless and hungry; twenty thousand and fifty thousand and a hundred thousand and two hundred thousand. They streamed over the mountains, hungry and restless-restless as ants, scurrying to find work to doto lift, to push, to pull, to pick, to cut-anything, any burden to bear, for food. The kids are hungry. We got no place to live. Like ants scurrying for work, for food, and most of all for land ...

– John Steinbeck, The Grapes of Wrath

The movement of the people described in this passage was primarily the result of the

A) effects of severe drought conditions on the Great Plains

B) high cost of the machinery needed to maintain family farms

C) overpopulation of the Midwest caused by the Homestead Act

D) construction of the interstate highway system