Methyl tetrachloride (MTC) is a chemical found in some pesticides, glues, and sealants. Exposure to MTC can cause people to develop asthma. In order to halve the nation's asthma rate, the government plans to ban all products containing MTC. The government's plan to halve the nation's asthma rate relies on which of the following assumptions?

Explanation

The correct answer is Option A: 'Exposure to MTC is responsible for no less than half of the nation's asthma cases.' This is the underlying assumption of the government's plan, as it directly correlates the ban on MTC products with a significant reduction in asthma cases. Without this assumption, the effectiveness of such a ban in achieving the goal of halving asthma rates would be unfounded.Option B is incorrect because the economic implications of MTC products do not directly affect their relationship with asthma cases. Option C is not pertinent to the assumption needed for the plan, as the epidemic status of asthma does not imply that banning MTC will lead to a decrease in cases. Lastly, Option D is incorrect because it suggests a beneficial role for MTC products in asthma, which contradicts the rationale behind the proposed ban.