___ moved us most was___ he liked after the old man for more than twenty years.为什么

题目

___ moved us most was___ he liked after the old man for more than twenty years.为什么
___ moved us most was___ he liked after the old man for more than twenty years.
A.That; that B.What; that C What; what D.That; what
我选的是D为什么错了、、、

答案