I wrote a letter to John for his help during my high school years. without which I  the college entrance exam.

A． would fail

B．would have failed

C．should fail

D．must have failed

人均GDP高于个人收入，不会受到下面哪一项因素的影响？（）

A.个人所得税

B.公司未分配利润

C.折旧

D.社会保障支付