Hi drew,
If you haven't already done so, I'd recommend reading the earlier forum posts for this question, especially Emily's (Post #3), Ben's (Post #8), and Adam's (Post #10), as they specifically discuss Answer B.
These can be found at the following link.
viewtopic.php?f=671&t=11746
I will only add that the argument's conclusion is that the new test should replace the old test, so any answer that provides anything negative regarding the new test whatsoever would weaken this argument.
Here, since the point of these tests is to prevent illness, there can be a downside to the tests being "too sensitive" in that their detection goes far below what is warranted/practical to prevent illness. Flagging many foods (and potentially recalling/banning them in response) that are actually safe for human consumption would likely have major negative consequences for food producers and for the general public.
Of course, if there were some way for the new test to determine the exact levels of
Salmonella bacteria and only flag the unsafe ones, that would solve the problem. Unfortunately, the test doesn't appear to have this capability as far as what we are told.
