听力原文：W: David, who are the street people？ How did they get to living in the street？M:

听力原文：W: David, who are the street people？ How did they get to living in the street？

M: Well, some of them lost their job, some of them have mental problem, and some of them drink.

Q: which of the following factors is not mentioned as a cause of becoming street people？

(14)

A．Unemployment.

B．Family break-up.

C．Mental problem.

D．Drinking.

请帮忙给出正确答案和分析，谢谢！