Official Solution:
Policy Speech: Critics of the new Clean Energy Bill argue that it will lead to higher energy costs due to the implementation of expensive renewable energy technologies. However, since the bill's passage, we have replaced a number of conventional power plants with renewable energy projects and the average cost of electricity from these renewable sources has consistently been lower than the national average each year, which demonstrates that the bill has effectively contributed to reducing overall electricity costs.
Which of the following, if true, most strengthens the argument in the policy speech?
A. The cost of setting up renewable energy projects has decreased globally due to technological advancements over the last five years.
B. Electricity costs were rising at a rate above the national average in the years immediately before the Clean Energy Bill was implemented.
C. Some of the renewable energy projects started under the Clean Energy Bill have been discontinued due to technological inefficiencies.
D. The average cost of electricity generated from conventional (non-renewable) sources that were phased out since the bill's passage has been consistently higher than the national average during the same period.
E. The price of electricity in areas outside the influence of the Clean Energy Bill has risen due to increased costs of non-renewable energy resources.
Correct Answer: D. The average cost of electricity generated from conventional (non-renewable) sources that were phased out since the bill's passage has been consistently higher than the national average during the same period. The argument could be weakened if the cost of electricity produced by the conventional plants that were replaced by renewable sources was lower. Let's say these old (and polluting) power plants were generating super cheap electricity. This would mean that replacing these old power plants would actually drive the average cost of electricity higher, which would in turn make it more expensive and contradict the argument that the Clean Energy Bill has been reducing the overall energy costs. This statement helps clarify and strengthen the argument by indicating that such situation cannot happen.
A. The cost of setting up renewable energy projects has decreased globally due to technological advancements over the last five years. This answer choice is irrelevant as we are not concerned with the setup costs. The answer choice wants you to go down an assumption staircase that if the setup cost is lower, then perhaps the overall cost would be lower but we don’t know how much lower it is (is it lower than conventional sources? Maybe but maybe not). Also, if we are making assumptions, what about operating costs? This option requires a number of assumptions and cannot be the answer. Eliminate.
B. Electricity costs were rising at a rate above the national average in the years immediately before the Clean Energy Bill was implemented. B) does not strengthen the claim about the ongoing impact of the bill on current electricity costs compared to non-renewable sources. We just know that the cost of electricity was running up and it is not clear what impact it has on the bill or the claim. Eliminate.
C. Some of the renewable energy projects started under the Clean Energy Bill have been discontinued due to technological inefficiencies. C) actually weakens the argument by suggesting problems with some renewable energy projects, contrary to the speech's claim of effectiveness. Eliminate.
E. The price of electricity in areas outside the influence of the Clean Energy Bill has risen due to increased costs of non-renewable energy resources. This is a trap answer choice. It tells us that areas outside of the influence of the Clean Energy Bill have seen their costs rise but it tell us nothing about the Clean Energy Bill areas - maybe they rose even more. This answer choice could be a contender if it compared the 2 areas but it does not, as it just tells one side of the story. This answer choice is designed to make you combine information from other answer choices (big no-no on the GMAT) and wants you to think that it means that the Clean Energy Bill therefore worked to reduce the energy costs but we don’t know how the rise in other areas compares to the clean energy bill areas. Eliminate.
Answer: D