A
选what还是where要看他们在从句中作什么成分
agree是不及物动词,不能直接接宾语
有agree with,on,about的用法,但是没有agree something with,on,about的用法
举个例子
i agree with you on this point
我在这点上同意你
用where代替on this point
this is where i agree with you或者this is which/what i agree with you on