Passage Summary: Environmentalists want to replace gas with methanol to stop benzene pollution, but the author points out that methanol creates formaldehyde instead, so the switch seems pointless since both cause cancer.

Conclusion: The proposal to switch from gasoline to methanol is not a worthwhile idea.

Reasoning: Although methanol avoids the production of benzene, it produces formaldehyde, and both chemicals are known to cause cancer.

Analysis: The author assumes that because both substances are carcinogens, the trade-off is a wash. To support the environmentalists' proposal, we need to find a reason why formaldehyde is 'better' than benzene—perhaps it is produced in much smaller quantities, breaks down faster in the atmosphere, or is less toxic to humans. Look for an answer that establishes a comparative benefit for methanol that outweighs the presence of formaldehyde. We are looking to bridge the gap between 'it produces a carcinogen' and 'it is still a better option than gasoline.'