Question

Harry Potter,for ___life had once been very difficult,achieved great success and ……

Harry Potter,for ___life had once been very difficult,achieved great success and finally beat Voldemort.
A.whose B.whom C.that D.him
答案是B，但为什么不能选A呢?希望得到详细的解释。

Answer 1

for whom life had once been very difficult 实际上是 life had once been very difficult for whom。whom 指Harry Potter ，此句是非限定性定语从句。life 是从句的主语，所以不需要whose。whom是for的宾语，又是定语从句的引导词。
Harry Potter是主语，achieved和 beat 是谓语，great success 和Voldemort.是宾语。
译文：生活曾经对harry potter是那么的艰难，（但）他还是取得了巨大的成功，打败了Voldemort.