Which of the of the following was not a cause of the Dust Bowl according to the reading ?

I don't know what you read or if this is supposed to be a multiple choice question, but I would say that a herd of wild zebras did not cause the dust bowl, because I can't come up with anything better. I know what caused the dust bowl so that was because of farmers not rotating crops, so if it was a multiple choice question you could put whatever is not this. Assuming that you have four options you could have a 75% shot at getting it if this is one of the options; however if it is not you just wasted a bit of time you could have spent actually figuring out the answer to the question.

Explanation: I hope this entire thing was not entirely useless

the answer is d. tariffs were raised by america's trading partners after the smoot-hawley tariff act, decreasing exports, and declining job rates.