请教GWD-TN-13的一道题~谢谢先！~

Which of the following, if true, most logically completes the passage?

A recent poll found that over 80 percent of the residents of Nalmed Province favored a massive expansion of the commuter rail system as a means of significantly easing congestion on the province’s highways and were willing to help pay for the expansion through an increase in their taxes. Nevertheless, the poll results indicate that expansion of the rail system, if successfully completed, would be unlikely to achieve its goal of easing congestion, because       .

2. of the less than 20 percent of residents not counted as favoring the expansion, about half claimed to have no opinion one way or the other.

3. the twice-daily periods of peak congestion caused by people commuting in cars have grown from about an hour each to almost two and a half hours each in the past 20 years.

4. expanding the commuter rail system will require the construction of dozens of miles of new railroads.

5. the proposed expansion to the commuter rail system will make it possible for some people who both live and work at suburban locations to commute by rail.

答案是A，想不通，请教各位NN们！~~

这道题是不是说：

80%的人赞成扩建铁路系统作为一种缓和拥挤的方式，他们也愿意交多点税来pay for 这次建设。

但是，该问卷结果显示，如果成功扩建该系统，也不能达到缓和拥挤的目的，因为__________

而选项A的话是不是有点和题目矛盾了。

因为题目已经说这80%的人已经同意扩建铁路来缓和拥挤

我是不是理解有错了？希望各位指点指点

80%的人赞成扩建铁路系统作为一种缓和拥挤的方式，他们也愿意交多点税来pay for 这次建设。

但是，该问卷结果显示，如果成功扩建该系统，也不能达到缓和拥挤的目的，因为__________

而选项A的话是不是有点和题目矛盾了。

因为题目已经说这80%的人已经同意扩建铁路来缓和拥挤

我是不是理解有错了？希望各位指点指点