The explanation for the dolphin die–off given by the research team most strongly supports which one of the following?

Jay-Etter on January 22, 2022

Hello,
We'd start this question by noting that the question is asking us the explanation for the die-off by the RESEARCH TEAM (RT) most strongly supports which one of the following? So even though the passage as a whole will conclude by arguing that the research team's explanation is implausible and it was probably synthetic pollutants that killed the dolphins, this question is asking us only about the RT's argument and not the authors. The RT's argument is in the third paragraph, so let's zoom in there and reread quickly if necessary.

A) Nope, they didn't tell us anything about the mechanisms by which brevetoxin affects dolphins vs. other marine animals.
B) Nope, nothing comparing the relative toxicity of P. Brevis
C) Tempting, because they said brevetoxin poisoning is a type of opportunistic bacterial infection. However, there could be a ton of other types of opportunistic bacterial infections other than brevetoxin poisoning, so no.
D) This one required a close read, but in line 32 they say "the emaciated appearance of many dolphins indicated that they were metabolizing their blubber reserves". So, it's not PCB poisoning that's causing them to be emaciated, it's rather the metabolization of their reserves. Then, metabolization is what's releasing the PCB into their bodies.
E) Our elimination of D helps us to see why this is the correct answer. In lines 32-40 they state that metabolized blubber causes PCBs to be released into the body, which exacerbates their condition and makes them more vulnerable to infection. So then PCB has a host of new negative effects when it is released from the blubber, and E must be correct.

Hope this helps, feel free to follow up.