英语:定语从句中,关系词何时只准用which 而不用that?

英语:定语从句中,关系词何时只准用which 而不用that?
只见过定语从句关系词只用that而不用which的情况..但请回答这一题:
He paid the boy $10 for washing ten windows,most of____ hadn't
been cleaned for at least a year.
A.these B.those C.that D.which
答案为什么选择D?难道是关系词只用which 而不用that的情况?

因为介词后面只能用which啊
which 代表物,作从句的主语,宾语,可引导非限制性和限制性定语从句
that 代表人或物,作从句的主语,宾语,表语,只引导限制性定语从句
只用which
1 关系代词作介词宾语,即 介词+关系代词,指物只能用which
Last night I had a dream in which I became a Nobel Prize winner.
2 非限制定语从句中,指物只能用which,亦可指整个前面的句子.
He reads English every day,which does good to his English study.
只用that
1 先行词为不定代词:one much everything all any ...
2 先行词被形容词最高级所修饰
3 先行词被序数词所修饰
4 先行词由only ,just ,very,right等修饰
5 在以which 开头的特殊疑问举重,避免重复用that.
6 先行词在从句中担任表语,从句的关系词用that.
够了咩?