New farm equipment did many things to urban America. Let's take a detailed look at each option:
A.New machinery contributed to soil erosion, which led to the Dust Bowl.
This did happen, however, this was due more to the lack of proper planting techniques and the decision to replant the native plants with a massive quantity of wheat.
B.New machinery led to overproduction, which led to an increase in the price of food.
According to the basic laws of economics, an overproduction of food would cause the price to decrease not increase. As a matter of fact, prices dropped so low that most farmers no longer made a profit.
C.New machinery led to new jobs for individuals such as sharecroppers.
The new machinery did lead to an increase in jobs, however, the drought caused many farms to fail and forced tens of thousands to flee towards California.
D.New machinery led to the banking crisis since farmers were unable to pay off loans.
This appears to be the only answer that properly matches with the prompt of Urban America, as a lack of income and loans on new farm equipment did bring about a banking crisis for farmers.
Therefore, the answer that best fits this question will be option D.
I hope I've helped! :)