请问GWD7-Q15， 关于whose的用法

GWD7-Q15

The city has proposed a number of water treatment and conservation projects the cost of which raises water bills high enough so that even environmentalists are beginning to raise alarms.

A.the cost of which raises water bills high enough so that

B.at a cost raising water bills so high that

C.at a cost which raises water bills high enough so

D.whose cost will raise water bills so high that

E.whose cost will raise water bills high enough so that

正确答案是D我选的是B

有2个问题：1，请问这里的"whose"是指代“projects"吗？我一直都以为”whose"只可以指代“人的”。

                        2，B为什么错了？

顶啊 等待NN~~

whose可以指代物

B为什么错我不知道

顶

貌似应该是costs吧

额..那不是全错了

不是这里的问题哦

是不是应该是at a cost of 固定搭配，表示“以.....为代价”啊~~~

thx~~

刚楼上一个at a cost of 以什么为代价也是解释的通~~

哈 看来这题大家帮我解决了！谢谢~~