Explanation

Reading the question: this prompt gives us a plan. As we've discussed, a plan is like an argument in which the conclusion is, "This thing is going to work." We're switching from three little cleaning rooms to two, with a more vigorous blasting of air. And as we've discussed before, since we have answer choices that start with "whether," we will be able to evaluate by analysis of extreme cases. But we can start with a basic relevance filter. The "goal" of the plan is to "speed up the process of entering the production facility." Let's filter based on which answer choices are relevant to that goal.

Applying the filter: choice (A) does not pass the filter; the cost is irrelevant to whether or not the plan will work as proposed to speed up entry. Choice (B) concerns saving time, but it's still fails to pass the filter, because the objective of the plan is to speed up entering the production facility, not save all time for everyone on the planet in every conceivable way. Choice (C) has some potential. We consider one case: the time in the extra-blasty room is the same as the current room. It doesn't alone guarantee that the plan will work, but it doesn't ruin the plan. But if the air blasting in the new room takes a really long time, that will outweigh the time saved in changing jacket, hat, and shoe coverings only twice rather than three times. So (C) is in and is a good candidate for the right answer. Choice (D) is out, because while it might impact whether this plan is the best plan, it doesn't impact whether this plan will work, which is what we are after. Choice (E) sounds possibly relevant, but isn't as grounded in the argument as (E). For all we know, exiting interferes in no way with entry, so (E) is not necessarily relevant to achieving the goal.

Logical proof: we have already established logical proof of (C) through analysis by cases. Logical proof does not have to come last, and you may often naturally find yourself alternating between applying a filter and using the negation test. You just want to be careful not to forget about your filter, as people often do when they dig into the answer choices. Another caveat: matching against a prediction or basic relevance is much faster than applying the negation test. The correct answer is (C).