求一道英语定语从句问题的详细说明,谢谢

求一道英语定语从句问题的详细说明,谢谢
The next question _____ was put to me by Mary.
A that I found it difficult to answer
B I found it difficult to answer
C I found difficult to answer
D I found difficult to answer it
这道题的正确答案给的是C ,我想知道这个句子还原后是什么样子的,不是i find it difficult to answer the question吗?it做的形式宾语,后面的不定式做的是真实宾语,但是如果the question做先行词的话他是做谁的宾语啊,是做answer的吗,是的话那前面的It怎么没有了啊,做find 的宾语吗,要是做的话,原句就是i find the question difficult to answer,有这种说法吗,麻烦高手给予详细解答,谢谢,急!