I have made __ I will never go back on my word

题目

I have made __ I will never go back on my word
A.that it clear B.it clear that C it that clear D clear that it 选什么?为什么?怎么翻译?

答案

B it clear that THAT 连词接从句 后面的事情就是IT
我已经说得很明白了,