Prep2012-Pack1-CR-071 VCR014016 Hard
　　Reasoning
　　What conclusion would the statements about utilities’ coal-related expenses support? Low-quality coal costs less per ton, but burning low-quality coal generates electricity less efficiently and produces more ash, which utilities must pay an increasing amount to dispose of. It's unclear whether overall coal purchasing costs are lower with low-quality or high-quality coal, since the lower price per ton of the former may counterbalance the need to buy more tons to generate the same amount of electricity. Although ash disposal is becoming more expensive, we are not told how that expense compares to those of the other factors mentioned; it may be negligible.
　　A. Correct. The information presented does not clearly support a conclusion about whether it's economically beneficial for coal-burning utilities to minimize their coal-purchasing costs. Therefore, utilities relying solely on this information cannot be assured that it is.
　　B. Since high-quality coal burns more efficiently, the utilities can buy less of it to generate the same amount of electricity, potentially compensating for its greater expense per ton.
　　C. The transportation costs per ton are probably about the same for low-quality coal as for high-quality coal. Therefore, they are probably a greater proportion of the cost per delivered ton of low-quality coal.
　　D. We are given no information about whether the cost to dispose of a ton of coal ash depends on the type of coal burned to generate that ash.
　　E. Even in the regions where coal-ash disposal is least expensive, it may still be expensive enough to encourage utilities to mine and burn more high-quality coal and thus generate less ash.　　
　　The correct answer is A.