#18 - Concept Reference, Must Be True, Author's Perspective

[Administrator]

Complete Question Explanation

The correct answer choice is (E).

Answer choice (A):

Answer choice (B):

Answer choice (C):

Answer choice (D):

Answer choice (E): This is the correct answer choice.

This explanation is still in progress. Please post any questions below!

[cleocleozuo]

Hi, I was hesitating between C and E but ended up choosing C.
My thought process of choosing C is that inline 50-52, it says that PCB poisoning is known to impair the functioning of the immune system and liver. Then the author presents an alternative hypothesis to account for "these facts". I thought "these facts" represent an impaired immune system and liver. The person then said that "brevetoxin may have been a contributing factor". So I thought the author thinks that even though the effects of brevetoxin is unknown, but it may hurt the immune system and liver anyways. (I know the author did not say this explicitly, but since this is an inference, I thought I could make this inference from "a contributing factor"). Could someone help me to see what's wrong with my thought process?

Many thanks!

[Jeremy Press]

Hi cleo!

A couple thoughts to help clarify the passage and steer your thought process in a different direction.

First, the author says in lines 47-48 that "the specific effects of brevetoxin on dolphins are unknown," so it would be very unlikely that the author would then embrace a hypothesis suggesting brevetoxin does have some very specific effects on liver and immune function.

Second, when the author refers to that "alternate hypothesis," the immediately following sentence suggests that the "sudden influx of pollutants" are the root cause of the damage to the dolphins' systems (likely, though maybe not certainly, including the liver and immune disorders).

And last, when the author writes that brevetoxin "may have been a contributing factor," that is in a sentence talking in general about the "die-off," and not specifically about individual physical effects. So there the author seems to mean the brevetoxin contributed to the die-off in general, but we don't know specifically how it contributed.

One other side note: even if we could connect brevetoxin to liver and immune damage, the author only says in the passage that brevetoxin "may" have been a factor. That wouldn't give us the kind of support we would need to make the stronger claim in answer choice C that brevetoxin "damages" (100% certainly) the liver and immune system.

I hope this helps!

Jeremy