Why does the professor mention that drought is often blamed as the cause of the Dust Bowl？

Why does the professor mention that drought is often blamed as the cause of the Dust Bowl？

A．To explain that many tenant farmers had to leave their land before the Dust Bowl era

B．To emphasize that the Dust Bowl resulted mainly from soil erosion

C．To show why the local population increased when rainfall returned to normal

D．To prove that the drought was the worst on record at that time

此题为多项选择题。请帮忙给出正确答案和分析，谢谢！