It is reported that there are various reasons more and more people feel depressed at this

问题补充：

It is reported that there are various reasons more and more people feel depressed at this time of year.

A. why

B. when

C. what

D. how

答案：

(答案→)A. why

B. when

C. what

D. how

解析：考查定语从句。先行词是reasons，且定语从句缺少状语，所以用why引导定语从句，在从句中作原因状语。选A。