do you have anything to say for yourselves?

Question

-do you have anything to say for yourselves?
-yes,there's one point ___ we must insist on.

A.why B.where C.how D./

我选了个B，答案是D，为什么？

Answer 1

这是一句宾语从句，如果要把one point还原到从句中就是we must insist on one point，这已经是一句完整的句子了，所以不能再用why,where,how，what之类的，要么不填，要么用that或which