[讨论]og-23 对OG解释的疑问

OG p504的23题题目如下：A cost-effiective solution to the problem of airport congestion  is to provide high-speed ground transportation between major cities lying 200 to 500 miles apart.The successful implementation of this plan would cost far less than expanding existing airports and would also reduce the number of airplanes clogging both airports and airways.
Which of the following ,if true,could proponents of the plan above most appropriately cits as a piece of evidence for the soundness of their plan?

D)Many new airports are being built in areas that are presently served by high-speed ground-transportation systems.

OG解释: D provides some evidence against the plan…..D by indicating that such an alternative is not by itself a solution to airport congestion.

OG认为D削弱.但个人认为.new airports 与problem of airport congestion以及expanding existing airports尚有一定差距, 因而不能削弱.

请大家讨论

谢谢weiyu的回答

我的疑问在D选项是否对结论起"削弱"作用. 题中要解决的问题是:the problem of airport congestion. 如果new airports also suffer such problems, then option D provides evidence against the conclusion. But from where we can draw the conclusion that many new airports are suffering congestion problem?

up!

我对这个解释也糊涂。请nn指点，谢谢。