Banded Nuthatch

[ashish2104]

Recently, orinthologists surveying the bird population of the remote forests of kamchatka peninsula reported sighting of a banded nuthatch. Most orinthologists consider the banded nuthatch to have become extinct in the 19th century, since the last verified sighting of a banded nuthatch was in 1895. It is therefore most reasonable to conclude that the orinthologists who claim to have spotted the banded nuthatch were mistaken.

Which of the following, if true,most seriously weaken the argument above?
A) Although experienced, the orithologists participating in the survey had never before visited the forests of kamchatka.
B)The banded nuthatch was always a rare bird, and the last verified sighting prior to 1895 was in 1815.
C) It is rare that a speices thought to be exitinct is found to be still in existince.
D)The lesser nuthatch, a bird found to be widespread in the forests of kamchatka, is very similar to banded nuthatch in appearance.
E)the orinthologits surveying the birds of kamchtka are among the mot respected and highly regarded in their field

OA later.

[grockit_andrea]

I'd go with B. The question asks you to weaken the argument's conclusion, which is that the ornithologists must have made a mistake, since the last verified sighting was in 1895. Choices A, C, and D all strengthen the argument's conclusion, making it more likely that the ornithologists made a mistake. Choice E is irrelevant; no matter how well-respected the ornithologists are, they could still make a mistake. If B were true, then the bird is probably quite rare or difficult to spot, so the interim between the last sighting and now wouldn't necessarily be an indication that the bird is extinct or that the ornithologists made a mistake.

[albatross86]

Fact: Last sighting of a BN was in 1895 --> thus considered extinct
Claim: Recent sighting of BN in kamchatka.

Conclusion: Claim is false because of Fact 1

WEAKENER

A. Their knowledge of Kamchatka is not evidently linked with the authenticity of the sighting - irrelevant.

B. It being a rare bird doesn't affect either the claim or the fact that it is considered extinct - irrelevant.

C. Rare, but possible - irrelevant.

D. This strengthens the argument by attacking the claim.

E. Respected / Highly regarded - this adds authenticity to their sighting. Weakens the argument that they were mistaken. Additionally the counterargument about other ornithologists claiming extinction - if these surveying ornithologists are among the respected ones, perhaps they have the right / experience to veto the previous claim?

Pick E imo.


EDIT: Andrea's explanation of B is excellent - I rescind my explanation of choice E, which is inaccurate and contrived since I missed the essence of choice B.

[ashish2104]

IMO B.

[sumanr84]

No doubt, B should be the answer.