Q24 - The Kiffer Forest Preserve...

[ZIYAOW681]

My reasoning process:


Conlusion: bear population in V will increase if the conditions remain the same.

In eight years, bear population in P increased (nearly doubled).
↓
How can population increase happen? → Only two ways: birth; migration.
↓
How can migration happen? → Only two ways: from places (outside P and) outside V; from places (outside P and) inside V
↓
So we can only get the population increase from: (N1) birth (inside P); (N2) migration from (outside P and) outside V; and/or (N3) migration from places (outside P and) inside V
↓
If in eight years we do not have N3 → with only N1 and/or N2, when all other conditions remain unchanged → cannot weaken
So to weaken the argument, we must have N3.
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We need the mere existence of N3, or how much N3 is also matters?
If in eight years we only have one bear of N3 → all remaining increase came from N1 and/or N2, when all other conditions remain unchanged → cannot weaken
So how much N3 is does matter.
↓
Thus, the more we can discriminate N3 from N1 and/or N2, the better an answer choice is.
(Sure, an ideal answer would be something like “N3 exists and is sufficiently large that we can ignore N1 and/or N2”)

A : the discrimination can be inferred here is N1 vs. N2+N3, but we need N3 rather than N1 to stands out → eliminate
B : yes N3 stands out here, but “only some” looks confusing → defer
C : like A, the discrimination can be inferred here is N1 vs. N2+N3 → eliminate
D : like A, the discrimination (if any) can be inferred here is N1 vs. N2+N3 → eliminate
E: the discrimination can be inferred here is N3 vs. N1 → defer

Now take a closer look at B and E:

Assume that in eight year there is no death / migration out of V, (we can go on without this assumption but it makes things easier since we can supply zero)
Information in B: N3 exists, N2 exists, N1 unknown
Information in E: N3 exists, N2 about zero, N1 about zero

N3 is good, N1/N2 is baaaaaaaad, so E is better.

[mswang7]

Premises: Most of the bears in AV reside in the north - KFP.
8 years, main road through KFP has been close, KFP bear pop doubled.
Concl: AV bear pop will increase if road is kept closed
Gaps: Correlation between bear pop in AV & KFP

A. Weakens - if it's by migration when the pop of KFP goes up, other areas should decrease accordingly so bear pop in AV will stay the same
B. Somewhat strengthens for the same reasons as A. Increase is not due to migration so it must be organic, although this doesn't tell us that increase in KFP also means overall increase in the valley
C. Soft language here could go either way - similar to B, some of the growth has been outside the valley which means some is still only within which doesn't help our argument
D. This would imply the increase within the valley could have been due to migration from other parts within, same logic as A
E. This straight up tells us bear pop (during this period in question) has not increased despite the road closure, severely weakening the argument