Passage Summary: Environmentalists are choosing a power plant that creates much more air pollution than the alternative, which seems to contradict their typical goals.

Conclusion: Environmentalists unanimously support building a waste-to-energy plant over a natural gas-fired plant.

Reasoning: The utility needs a new plant, and despite the waste-to-energy option producing triple the air pollution of the gas option, environmentalists prefer it.

Analysis: To strengthen the environmentalists' position, we need to find a 'hidden' environmental benefit of the waste-to-energy plant that outweighs its high air pollution. The stimulus presents a trade-off, so the correct answer will likely address a different environmental problem that the waste plant solves. For instance, if the trash would otherwise go to a landfill and produce even more harmful methane or groundwater contamination, the air pollution might be the lesser of two evils. Look for an answer that provides a broader ecological context.