The problem is ___he doesn't believe anything__you said to him.

问题描述:

The problem is ___he doesn't believe anything__you said to him.
A.that ,/ B./.that
请在说出答案的同时,说出另一项不对的原因

其实两个都可以用THAT.但是既然给了选项只能选一个.
第一个是表语从句,THAT不能省略,第二个是定语从句,且THAT在从句中宾语,是可以省略的.
所以选A.