preptest 8 section 4 question 11 Forum

[fire_fried_rice]

This question, though I got it correct, still gives me a headache. I was able to correctly identify answer choice A through elimination. However, I actually had hard time having the confidence of saying A was the correct choice because I could not understand why A IS the answer choice.
The conclusion of the stimulus would be : severe pollution weakened the immune system of the seals. Thus, if we are to find an answer choice that can support the explanation, we would have to find something that confirms the conclusion or exclusion of anything that would say otherwise.
Of course, I can intuitively understand slightly as to why A might be correct. The drop in the pollution of shellfish and seabirds might indicate that the pollution also affected them as well, thus saying that it is the pollution that is causing all the trouble. However, isn't this thinking "extra" step? The answer choice itself is insufficient to really give support to the explanation. I would really love some advice for such problems.

Also in general, when you are able to get a question right through elimination, but isn't quite sure as to why the remaining answer choice is the answer and still have questions when you are doing the BR, what do you? I find that doing BR has its limits in that I cannot get that little "push" to make me think out of my box. Such as this question, I have trouble understanding it by myself. How do you guys overcome this problem??

[Deardevil]

The conclusion is that there must be pollution that weakens the seals' immune system.

(A) At various times during the last ten years,
several species of shellfish and seabirds in the North Sea have experienced unprecedentedly steep drops in population.
Like you state, we can INFER from this that it MAY be severe pollution;
we do not have absolute confidence, but this 100% STRENGTHENS the idea.

(B) By reducing pollution at its source,
Northern Europe and Scandinavia have been taking the lead in preventing pollution from reaching the waters of the North Sea.
I fail to see how this is relevant;
sure, it is nice that these places are leaders in limiting pollution, but it tells nothing of pollution being the problem.

(C) For many years, fish for human consumption have been taken from the waters of the North Sea.
Irrelevant once again; way off the mark.

(D) There are two species of seal found throughout the North Sea area, the common seal and the gray seal.
Do we care?

(E) The distemper caused by the virus was a disease that was new to the population of North Sea seals in May 1988,
and so the seals’ immune systems were unprepared to counter it.
Well, this actually WEAKENS the argument by introducing another factor in causing the drop in the number of seals.

What to take from this? You are not trying to confirm the conclusion; rather, you just wish to give it that little push to make it more plausible.
Similarly, for questions that ask you to weaken the argument, you are not disproving, but making it less likely to be the case. Hope that helps.

[fire_fried_rice]

The conclusion is that there must be pollution that weakens the seals' immune system.

(A) At various times during the last ten years,
several species of shellfish and seabirds in the North Sea have experienced unprecedentedly steep drops in population.
Like you state, we can INFER from this that it MAY be severe pollution;
we do not have absolute confidence, but this 100% STRENGTHENS the idea.

(B) By reducing pollution at its source,
Northern Europe and Scandinavia have been taking the lead in preventing pollution from reaching the waters of the North Sea.
I fail to see how this is relevant;
sure, it is nice that these places are leaders in limiting pollution, but it tells nothing of pollution being the problem.

(C) For many years, fish for human consumption have been taken from the waters of the North Sea.
Irrelevant once again; way off the mark.

(D) There are two species of seal found throughout the North Sea area, the common seal and the gray seal.
Do we care?

(E) The distemper caused by the virus was a disease that was new to the population of North Sea seals in May 1988,
and so the seals’ immune systems were unprepared to counter it.
Well, this actually WEAKENS the argument by introducing another factor in causing the drop in the number of seals.

What to take from this? You are not trying to confirm the conclusion; rather, you just wish to give it that little push to make it more plausible.
Similarly, for questions that ask you to weaken the argument, you are not disproving, but making it less likely to be the case. Hope that helps.

Yes, I clearly understand that the point of strengthening a conclusion is not trying to confirm it, but as how you said it, give it a little push. But to me, I find answer choice A to require us to think extra few steps to give that little push. What if the steep drop in the population was due to something else than the pollution? I feel that some indication that it was the pollution that affected the shellfish and seabirds to really provide some "psuh". Or is this sort of extra few steps necessary part that I have to think? I thought for LSAT, we should try to eliminate our personal views and thoughts/knowledge and use only the information available in the stimulus.

[Deardevil]

Sometimes, questions may require some leaps or assumptions that you will need to get used to.
You are right in that it definitely could be something else that causes the steep drop, such as an increase in the population of its main predator.
Nevertheless, the fact that seals, shellfish, and seabirds share the same environment and die (correlation) lends credence to this answer choice.

Think about it this way.
If I tell you that a restaurant is super unsanitary because the workers are getting sick,
this argument can be strengthened by the fact that customers are becoming ill as well.
You may not believe my claim earlier, but with this new information, you should at least have a little more faith, EVEN if it is not true.

So to strengthen this particular issue,
(A) shows that not only seals are fading due to potential pollution, but also shellfish and seabirds because they all inhabit the area.
Again, it may very well be another cause, but this is not a MBT question, so if a choice possibly boosts a claim in even a marginal way, it's right.