Gas-fired and oil-fired power plants emit some pollutants into the

Question

Gas-fired and oil-fired power plants emit some pollutants into the air. However, coal-fired plants, as presently engineered, emit far more noxious air pollutants, causing acid rain to fall hundreds of miles away from the plants themselves. Therefore, in order to reduce air pollution, we should close down the coal-fired plants and replace them with gas and oil-fired plants.

Which of the following, if true, would most weaken the conclusion above?

A. In addition to the air emissions from coal-fired power plants, mining coal can pollute water, while gas and oil-fired plants pollute only air.

B. Coal plants can easily be redesigned to eliminate most emissions into the atmosphere.

C. Gas-fired power plants are more cost efficient than coal-fired power plants.

D. As supplies of oil decline, the demand for natural gas and coal will increase.

E. Engineers have developed a model to reduce emissions from oil and gas-fired plants to an imperceptible amount.

This is a  CR Butler Question

Check the links to other Butler Projects:
 
  Data Sufficiency Butler  
  Problem Solving Butler  
  Reading Comprehension Butler

dhart · Answer

looks option B ) the coal plants can be rringineered to completely reduce reduce emissions.

abhishekb1352 · Answer

Answer is Option B as it says the coal powered plants can be easily redesigned to reduce the amount of pollutants it emits into the surrounding air. This suggests that closing down coal powered plants and replacing them with gas and oil powered plants is not such a good idea.

Vivek1707 · Answer

A. This actually strengthens the argument by showing coal has additional environmental downsides beyond air pollution.
B. Yup, this weakens If coal plants can be redesigned to eliminate most emissions, then there's much less reason to shut them down and replace them. This directly undercuts the proposed solution.
C. Lower costs make the proposal more attractive, but the argument is about reducing air pollution, not saving money.
D. Future demand for fuels doesn't tell us whether replacing coal plants would reduce air pollution.
E. This strengthens the conclusion. If gas- and oil-fired plants can be made even cleaner, replacing coal plants becomes an even better solution.

odionam · Answer

Given: Pollution from gas and oil are less noxious than Coal-fired therefore Coal-fired plants replace with gas and Oil-fired plants. to weaken the conclusion we have to find advantage of coal-fired which is directly given in option B 
A is strengthner 
C and D are irrelevant as they are talking about cost and demand
 E is again strenghtner

G780MAT · Answer

Ans B is only weakening the conclusion

Minka99 · Answer

The conclusion is:  in order to reduce air pollution, we should close down the coal-fired plants and replace them with gas and oil-fired plants .
Weakening the conclusion would work if we 1) discredit positive traits of gas-fired and oil-fired power plants (e.g. they cause way less air pollution than coal-fired plants, etc.) OR 2) claim that coal-fired plants are not as harmful in respect to air pollution as originally claimed.
Important: price, society's opinion, etc. are not relevant here as our conclusion only mention air pollution; thus, the answer we are looking for must directly address this topic in either of the 2 stated ways.
Correct answer:  B  because it states that the air pollution caused by coal-fired plants can be avoided if they are redesigned to emit those pollutants higher up into the atmosphere.

Bunuel · Answer

Official Explanation

This is a Weaken question. The correct choice will make the conclusion less likely to follow from the stated evidence.

The author's conclusion appears after the keyword "therefore." The author believes that in order to reduce air pollution, we should close down coal-fired plants and replace them with gas- and oil-fired plants. As evidence, the author points out that coal-fired plants emit far more noxious air pollutants than do the other two types of plants.

Note that the author is making an extreme recommendation. Closing down plants and replacing them with new plants that use different fuel is a major operation. The author must be assuming that such an extreme measure is really needed in order to reduce pollution - that there is no other solution. The correct choice will make it less likely that the coal-fired plants really should be replaced with gas- and oil-fired plants in order to reduce pollution. It might suggest some less drastic measure that would suffice or point to some unstated negatives about gas- and oil-fired plants (with regard to air pollution) that make the switch less attractive. It's hard to know exactly what the GMAT will come up with, but having the general prediction in mind will make it much easier to eliminate wrong choices.

(B) suggests an alternative, less drastic measure and is correct. If coal plants can "easily" be redesigned to eliminate most emissions, then the recommendation to replace the entire plant in order to reduce air pollution is weakened.

(A) points out another negative of coal but is irrelevant to the argument in the stimulus, which addresses only air pollution, not water pollution or all pollution.

(C) is an irrelevant comparison because the argument is about pollution, not about cost efficiency. This choice also fails to mention oil-fired plants.

(D) does not address the three fuels' effect on air pollution, so it is irrelevant to the argument in the stimulus.

(E) is a 180. It would strengthen the argument by making gas- and oil-fired plants look even more attractive in terms of emissions.

Gas-fired and oil-fired power plants emit some pollutants into the

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Critical Reasoning (CR) Questions

­Gas-fired and oil-fired power plants emit some pollutants into the

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

Gas-fired and oil-fired power plants emit some pollutants into the