Thanks for the question! So first, we should note that this question is asking for the answer choice that does not support the claim, as it is an except question.
Now we can get into the stimulus itself, which is pretty short. Essentially, we’re told that even if their departments are obviously overstaffed, midlevel managers at large corporations probably won’t suggest to cut staff in the departments that they manage.
Now let’s take a look at (D), which tells us that departmental workloads at most large corporations will fluctuate significantly and unpredictably. This strengthens the author’s argument because it gives us a reason midlevel managers at large corporations might keep bloated staffs. It’s better to have too many people than too few people, and so if there’s lots of fluctuations, it might be a good idea to have too many people so that when there’s a significant upward fluctuation, the department can handle it.
The correct answer, (E), doesn’t support the claim, as it is completely irrelevant. Retirement incentives and other incentives for reducing staff won’t explain the fact that midlevel managers don’t actually reduce staff.
Hope this helps. Feel free to ask any further questions that you might have.