Safety inspector: The number of laboratory samples of rabies virus sent through the university delivery service has recently grown dangerously high. We need to limit this use of the service.Biologist: There is no need for a limit. The university delivery service has been handling rabies virus samples for 20 years with no accidents.As a rebuttal of the safety inspector's claim, the biologist's reasoning is flawed in that itThe inspector’s point is not simply that rabies samples are being delivered. The point is that the number of samples has recently become dangerously high. The biologist replies that there have been no accidents in 20 years, but that past safety record does not directly answer the new concern about increased volume.
The flaw is that the biologist ignores the changed risk level created by the recent increase.
(A) fails to explain why the number of samples sent through the service has increased
Wrong. The reason for the increase is not necessary. The issue is whether the increase creates enough risk to justify a limit.
(B) fails to focus specifically on the issue of rabies virus samples
Wrong. The biologist does focus on rabies virus samples.
(C) overlooks the possibility that there has been a change in the hazardousness of the rabies virus samples themselves
Wrong. The inspector’s concern is about the number of samples, not whether each sample has become more dangerous.
(D) offers no defense of the university's need for continued delivery of rabies virus samples
Wrong. The argument is about safety risk, not whether the deliveries are useful or necessary.
(E) does not address the potential for harm that is posed by the recent increase in the number of samples sent through the service
Correct. The biologist relies on a past accident-free record, but does not address whether the recent increase in volume creates a new danger. That is exactly the inspector’s concern.
Answer: (E)