Critical Reasoning

It's wrong because it doesn't answer the question:

Which of the following, if true, most strongly supports the claim that the proposal, if carried out, will have the announced effect?

How does an answer to this question help to prove that the proposed plan will have and advertised effect?

This answer choice is more of an assumption on which the Fire Commissioner bases his proposal. But the question doesn't ask to state an assumption. Our task is to find an evidence that (if true) will support the plan, i.e., will show that the plan will result in benefits it claims.