题目选项分析

Electric utilities pay less for low-quality coal per ton delivered than for high-quality coal. Yet more low-quality coal than hogn-quality coal must be burned to generate the same amout of electricity. Moreover, per ton of coal burned, low-quality coal generates more ash than does high-quality coal, and the disposal of ash is becoming more and more expensive.

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

【选项】A coal-burning utility migth not be assured of benefiting economically by always adhering to the policy of keeping its overall coal purchasing costs as low sa possible.