求大神解决一到gre逻辑题!

问题描述:

求大神解决一到gre逻辑题!
Which of the following most logically completes the argument?Alivia‘s government has approved funds for an electricity-generation project based on the construction of a pipeline that will carry water from Lake Cylus,in the mountains,to the much smaller Lake Tifele,in a nearby valley.The amount of electricity generated will be insufficient by itself to justify the project’s cost,even if the price of imported oil-Alivia‘s primary source of electricity-increases sharply.Nonetheless,the pipeline project is worth its cost,because ——
(A) the price of oil,once subject to frequent sharp increases,has fallen significantly and is now fairly stable
(B) the project could restore Lake Tifele,which is currently at risk of drying up and thus of being lost as a source of recreation income for Alivia
(C) the government of Alivia is currently on excellent terms with the governments of most of the countries from which it purchases oil
(D) it would cost less to generate electricity by moving water from Lake Cylus to lake Tifele than to do so by moving water from Lake Cylus to another valley lake
(E) Alivian officials do not expect that the amount of electricity used in Alivia will increase substantially within the next ten years
这道题为什么选B?我觉得选D.B不是引入了新的内容了么?答案来自于陈虎平36套2014年01月.然后网上说选D.那到底是选什么?

大湖向小湖流水发电,入不敷出,哪个事实成立会使得这个项目不亏?
选B是因为B所说的事实(拯救了能创造收入的小湖)可以带来额外收益.这道题已知的条件是亏损的,问哪个事实能使它不亏损,那么与之相关的赢利因素就不能算作新内容(因为这个赢利是以这个项目开展为条件的.如果说该*另外卖东西赚钱,就是新内容了).可以理解吧?
而D说从大湖向小湖运水比向其他湖运水花费小,只能说明这个项目亏的相对少,还是没解决worth its cost的问题.