Gasohol

Hello @Anna2020, First I will break down this argument. Conclusion: There should be a greater use of gasohol. Premise 1: Higher octane rating and fewer carbon monoxide emissions. Premise 2: Doesn't add more carbon dioxide than plants can remove. The 4 wrong answers are going to strengthen the argument. The right answer will either weaken it or do nothing. Answer choice D is a pretty strong supporter of the argument, so we can eliminate it. However, I can see why answer choice C was confusing. For this question, it is safe to assume that fuel efficiency is a good thing. C says that cars burn more gasohol per KM than they would burn gasoline. This means that gasohol is less efficient, which makes C the right answer by weakening the argument.