[求助]Prep2012-Pack1-CR-071 Electric utilities

原文如下：

Electric utilitiespay less for low-qualitycoal per tondelivered thanforhigh-qualitycoal. Yet more low-quality coal

than high—quality coal must be burned to generate the same amount of electricity. Moreover, per ton of coal burned,low-quality coal generates more ashthan does high-quality coal, and the disposal of ashis becoming more and moreexpensive.

The considerations above,if true, most strongly support which of the following claims?

A.   A coal-burningutility might not be assured of benefiting economically by alwaysadhering tothe policy ofkeeping its overall coal purchasing costs aslow as possible.

B.   In those regions where the cost of disposing of coal ashis negligible,it is moreexpensivefor coal-burningutilities to use high-qualitycoal thanlow-quality coal.

C.   Transportation costs represent a smaller proportion of the cost per delivered tonfor low-quality coal thanforhigh-qualitycoal.

D.   It isno less expensive to dispose of a ton of coal ash that results from theburning of high-qualitycoal than it isto disposeofa ton of coal ash that results from the burningoflow-qualitycoal.

E.   In regions where coal-ash disposal is the least expensive, reservesoflow-quality coal are likely to decline at a faster rate than are reservesofhigh-quality coal.

OA A

E选项的解释是 Even in theregions wherecoal-ash disposal is least expensive, itmay still beexpensiveenoughto encourage utilities to mine and burnmore high-quality coal andthus generate less ash.

但是E选项中有 ...are likely to... ，也就是说表示煤尘在处理成本最低的地区，低质量煤储量较高质量煤储量可能减少的更快。虽然这句话去掉 “are likely to”是一定错的，但是这里加上了这个可能性，我读起来觉得也没有问题。

不知道怎么理解呢？