Electric utilities pay less for low-quality coal per ton delivered than for high-quality coal. 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 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 claims?

A. A coal-burning utility might not be assured of benefiting economically by always adhering to the policy of keeping its overall coal purchasing costs as low as possible.
B. In those regions where the cost of disposing of coal ash is negligible, it is more expensive for coal-burning utilities to use high-quality coal than low-quality coal.
C. Transportation costs represent a smaller proportion of the cost per delivered ton for low-quality coal than for high-quality coal.
D. It is no less expensive to dispose of a ton of coal ash that results from the burning of high-quality coal than it is to dispose of a ton of coal ash that results from the burning of low-quality coal.
E. In regions where coal-ash disposal is the least expensive, reserves of low-quality coal are likely to decline at a faster rate than are reserves of high-quality coal.

Can someone provide detailed explanations of the answer choices. Thanks!

Why D is wrong?

D is assumption , right? What if disposal of Coal ash from low quality coal cost $10 and disposal of Coal ash from High quality coal cost $50.

Assumption is hidden premise--> Strengthner

D. It is no less expensive to dispose of a ton of coal ash that results from the burning of high-quality coal than it is to dispose of a ton of coal ash that results from the burning of low-quality coal.
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YOU CAN, IF YOU THINK YOU CAN

Electric utilities pay less for low-quality coal per ton delivered than for high-quality coal. 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 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 claims?

A. A coal-burning utility might not be assured of benefiting economically by always adhering to the policy of keeping its overall coal purchasing costs as low as possible. can be proved from the passage
B. In those regions where the cost of disposing of coal ash is negligible, it is more expensive for coal-burning utilities to use high-quality coal than low-quality coal. output of low quality coal is less, probable lot more low quality coal needs to be burned to match the output of high quality coal and that may equalise or exceed the cost for generating power from low quality coal
C. Transportation costs represent a smaller proportion of the cost per delivered ton for low-quality coal than for high-quality coal. Transportation cost is out of scope
D. It is no less expensive to dispose of a ton of coal ash that results from the burning of high-quality coal than it is to dispose of a ton of coal ash that results from the burning of low-quality coal. passage does not compares costs of low quality ash and high quality ash
E. In regions where coal-ash disposal is the least expensive, reserves of low-quality coal are likely to decline at a faster rate than are reserves of high-quality coal. can't be sure,people might use low quality coal because of cost reasons and they might not like to use low quality coal for lower output
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