首先排除A.D
至于C agree on意为“达成协议”,主语应是复数,且与题意不符
agree to 意为“同意、赞成、接受、答应”,后接名词.
给你几个例句：Do you agree to my plan?
你接受我的计划吗?
Neither father nor mother would agree to your plan.
爸爸妈妈都不会同意你的计划.
We must agree to differ on this.
我们得承认在这一问题上有分歧.