For many cities in the world,there is no room to spread out further,____ New York is an example.

问题描述:

For many cities in the world,there is no room to spread out further,____ New York is an example.
A.for which B.in which C.of which D.from which
这里先行词到底是 many cities ,还是there is no room to spread out further,这一整句话?如果是there is no room to spread out further这一整句做先行词,那不就相当于New York is an example of there is no room to spread out further for many cities in the world.可是OF是介词,后面也不能加句子呀?

C
先行词就是 many cities ,纽约是其中之一,所以说 of which.