单项选择His father suddenly died, ________ made it impossible for him to go abroad.

1. A.
   that
2. B.
   which
3. C.
   whom
4. D.
   for

根从所给的四个选项中选择最佳答案

His father suddenly died, ______made it impossible for him to go abroad．

[　　]

A．that　　　B．which　　　C．as　　　D．that