at a cost

yidiyuehans

the city has proposed a number of projects---------- even environmentalists are begining to raise alarms

B at a cost raising water bills so high that
D whose cost will raise bills so high that

帮帮忙吧 马上就考试啦

supermanlee

D

卮言浅夏

whose可以指物.
propose不用成本，而B里面at a cost做状语修饰了propose显得连提议一下就要花很多钱。合理逻辑含义是project要话很多钱。

yidiyuehans

谢谢，学习了~
一看whose先排除了...