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OG 12 8.4 #23

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OG 12 8.4 #23

by Ludacrispat26 » Tue Nov 10, 2009 9:50 am
A drug that is highly effective in treating many types of infection can, at present, be obtained only from the bark of the ibora, a tree that is quite rare in the wild. It takes the bark of 5,000 trees to make one kilogram of the drug. It follows, therefore, that continued production of the drug must inevitably lead to the ibora's extinction.

Which of the following, if true, most seriously weakens the argument above?

(A) The drug made from ibora bark is dispensed to doctors from a central authority.
(B) The drug made from ibora bark is expensive to produce.
(C) The leaves of the ibora are used in a number of medical products.
(D) The ibora can be propagated from cuttings and grown under cultivation.
(E) The ibora generally grows in largely inaccessible places.

OA: D

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I understand the rationale behind the OE given in the book, and originally had D before I switched to E. What I was wondering was: is it not true that, in E, if the plant was to be "inaccessible," which I took to mean "not able to be accessed via humans," then it would not go extinct (again via humans)? Also, does the adverb "largely" change the meaning of "inaccessible?"

Thanks for any info. I was on such a hot streak (first 22 right), and then hit this roadbump, and just wanted further feedback/thoughts. Thanks!
Last edited by Ludacrispat26 on Tue Nov 10, 2009 7:37 pm, edited 1 time in total.
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Re: OG 12 8.4 #23

by Testluv » Tue Nov 10, 2009 7:34 pm
Ludacrispat26 wrote:A drug that is highly effective in treating many types of infection can, at present, be obtained only from the bark of the ibora, a tree that is quite rare in the wild. It takes the bark of 5,000 trees to make one kilogram of the drug. It follows, therefore, that continued production of the drug must inevitably lead to the ibora's extinction.

Which of the following, if true, most seriously weakens the argument above?

(A) The drug made from ibora bark is dispensed to doctors from a central authority.
(B) The drug made from ibora bark is expensive to produce.
(C) The leaves of the ibora are used in a number of medical products.
(D) The ibora can be propagated from cuttings and grown under cultivation.
(E) The ibora generally grows in largely inaccessible places.

OA: D

-------------------------------------------------------------

I understand the rationale behind the OE given in the book, and originally had E before I switched to D. What I was wondering was: is it not true that, in D, if the plant was to be "inaccessible," which I took to mean "not able to be accessed via humans," then it would not go extinct (again via humans)? Also, does the adverb "largely" change the meaning of "inaccessible?"

Thanks for any info. I was on such a hot streak (first 22 right), and then hit this roadbump, and just wanted further feedback/thoughts. Thanks!
Hi ludacrispat26,

I can understand why you were tempted by choice E. In your comments above, you refer to choice D as stating "inaccessible". I am going to assume you meant choice E.

First of all, as a matter of strategy, because it is a lot easier to see that D weakens than it is to see that E weakens, you should just pick D. The test-maker often makes it harder to explain why a certain answer choice is wrong than it is to see why the right answer is right. So, because we know D definitely weakens we should select it even though we are worried about E. (We don't want to over-use POE and play ourselves into the test-maker's hands).

Why is E wrong? "largely inaccessible" is not the same as "inaccessible". In fact, the choice could not have been a valid answer choice option had it read just "inaccessible": We know from evidence in the stimulus that the drug DOES get made and that it can only get made from ibora bark. And, of course, they have to somehow access it in order to extract ingredients from the bark to make the drug. So, on this interpretation, the choice would be contradicting stated (or inferred) evidence.

The evidence is always given to the author and is true information. The GMAT will not provide answer choices in strengthen/weaken that contradict the evidence. This is because in strengthen/weaken questions the question instructs us to treat the answer choices as facts. We also have to treat the evidence as fact. And contradictory facts cannot exist (ie, the sky cannot be blue and red at the same time). However, in a strengthen/weaken question, if you do encounter an answer choice that you think is for sure contradicting evidence, then eliminate it.

But, of course, the choice says "largely inaccessible" and the word "largely" definitely lends some meaning to the choice (again, without "largely" the GMAT could not have fairly included it as an answer choice option.) We know from the stimulus that we extract the bark IN SPITE of it being "largely inaccessible." "Largely inaccessible" just means "difficult to access". And largely inaccessible places or difficult to access places is not the same as unknown places. So, this fact would not hurt the conclusion that continued production of drug would inevitably lead to extinction of the ibora. Now, if the choice had said "largely unknown places" then it would definitely be a weakener.

Another way of weakening the argument is if a fact suggested that, in the future, there would be new ways of making the drug; new ways that didn't require the ibora. (The passage states: "A drug that is highly effective in treating many types of infection can, at present, be obtained only from the bark of the ibora, a tree that is quite rare in the wild.")
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by Ludacrispat26 » Tue Nov 10, 2009 7:41 pm
Testluv,

Thanks so much for the awesome response! It was much appreciated.
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