Critical Reasoning (CR) | Re: Gas-fired and oil-fired power plants emit some pollutants into the air

­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 imperceptibleamount.