I'm interested in ______ you have saidA.all thatB.all whatC.thatD.which我选的是that 但答案给的是all that 到底怎么回事呢?麻烦高手告诉下!

I'm interested in ______ you have saidA.all thatB.all whatC.thatD.which我选的是that 但答案给的是all that 到底怎么回事呢?麻烦高手告诉下!
I'm interested in ______ you have said
A.all that
B.all what
C.that
D.which
我选的是that 但答案给的是all that 到底怎么回事呢?麻烦高手告诉下!

I'm interested in ______ you have saidA.all thatB.all whatC.thatD.which我选的是that 但答案给的是all that 到底怎么回事呢?麻烦高手告诉下!
这句话有两种说法
一是 All that 这是定语从句 先行词是all 如果只有that 那就没有先行词了 当然也不对了
二是 What 这句话就是宾语从句 和in是介宾结构 What是宾语从句里做宾语

that引导定语从句需要有先行词即that前应该有一个名词或者代词作为interested in的宾语，all为代词，代指“你说的东西”

你选TAHT 的话，就等于把 that you have said当作名词性从句了，而名词性从句不能用that引导，你可以用 what you have said 就对了。
而 all that 中all 做先行词，that you have said做定语从句，这是对的。

若选that 这主句缺宾语。all 做宾语