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# Although exposure to asbestos is the primary cause for

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Although exposure to asbestos is the primary cause of [#permalink]

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11 Dec 2007, 07:28
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Although exposure to asbestos is the primary cause of mesothelioma, a slow-developing cancer, researches believe that infection by the SV40 virus is a contributing cause, since in the United States 60 percent of tissue samples from mesotheliomas, but none from healthy tissue, contain SV40. SV40 is a monkey virus; however, in 1960 some polio vaccine was contaminated with the virus. Reseaches hypothesize that this vaccine was the source of the virus found in mesotheliomas decades later.

Which of the following, if true, most strongly supports the researchers' hypothesis?

(A) SV40 is widely used as a research tool in cancer laboratories.

(B) Changes in the technique of manufacturing the vaccine now prevent contamination with SV40.

(C) Recently discovered samples of the vaccine dating from 1960 still show traces of the virus.

(D) In a small percentage of cases of mesothelioma, there is no history of exposure to asbestos.

(E) In Finland, where the polio vaccine was never contaminated, samples from mesotheliomas do not contain SV40.

[Reveal] Spoiler: OA

Last edited by mikemcgarry on 24 Sep 2015, 11:34, edited 2 times in total.

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Re: Although exposure to asbestos is the primary cause of [#permalink]

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11 Dec 2007, 21:58
tarek99 wrote:
Although exposure to asbestos is the primary cause of mesothelioma, a slow-developing cancer, researches believe that infection by the SV40 virus is a contributing cause, since in the United States 60 percent of tissue samples from mesotheliomas, but none from healthy tissue, contain SV40. SV40 is a monkey virus; however, in 1960 some polio vaccine was contaminated with the virus. Reseaches hypothesize that this vaccine was the source of the virus found in mesotheliomas decades later.

Which of the following, if true, most strongly supports the researchers' hypothesis?

a) SV40 is widely used as a research tool in cancer laboratores.

b) Changes in the technique of manufacturing the vaccine now prevent contamination with SV40.

c) Recently discovered samples of the vaccine dating from 1960 still show traces of the virus.

d) In a small percentage of cases of mesothelioma, there is no history of exposure to asbestos.

e) In Finland, where the polio vaccine was never contaminated, samples from mesotheliomas do not contain SV40.

Quite honestly, after reading the passage for the first time, I didn't know what the jack it meant

After re-reading with more focus, I sort of figure it out like this:

Researchers hypothesize that the cause of mesotheliomas, a slow- developing cancer, is SV40 virus, not the exposure to asbestos. Their reason is that SV40 is found in mesotheliomas cells and not found in healthy cells. Choice D says that in some small cases of mesotheliomas there was no exposure to asbestos. This proves that asbestos is not the only cause of the cancer, and in turn strengthens the conclusion that SV40 virus is the cause of the cancer in these cases.

a. is irrelevant
b. irrelevant
c. traces of the virus found shows that vaccines was comtaminated, but does not strengthen the conclusion that the SV40 virus causes cancer. vaccine here is general, not specific to polio. Thus can not apply.
e. This weakens the conclusion. This particular fact shows that where polio vaccine is absent of SV40 virus, mesotheliomas contains no SV40. Thus in this case, SV40 is not the cause of the cancer. This finding weakens the researchers' hypothesis.

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Re: Although exposure to asbestos is the primary cause of [#permalink]

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11 Dec 2007, 22:39
tnguyen707 wrote:
tarek99 wrote:
Although exposure to asbestos is the primary cause of mesothelioma, a slow-developing cancer, researches believe that infection by the SV40 virus is a contributing cause, since in the United States 60 percent of tissue samples from mesotheliomas, but none from healthy tissue, contain SV40. SV40 is a monkey virus; however, in 1960 some polio vaccine was contaminated with the virus. Reseaches hypothesize that this vaccine was the source of the virus found in mesotheliomas decades later.

Which of the following, if true, most strongly supports the researchers' hypothesis?

a) SV40 is widely used as a research tool in cancer laboratores.

b) Changes in the technique of manufacturing the vaccine now prevent contamination with SV40.

c) Recently discovered samples of the vaccine dating from 1960 still show traces of the virus.

d) In a small percentage of cases of mesothelioma, there is no history of exposure to asbestos.

e) In Finland, where the polio vaccine was never contaminated, samples from mesotheliomas do not contain SV40.

Quite honestly, after reading the passage for the first time, I didn't know what the jack it meant

After re-reading with more focus, I sort of figure it out like this:

Researchers hypothesize that the cause of mesotheliomas, a slow- developing cancer, is SV40 virus, not the exposure to asbestos. Their reason is that SV40 is found in mesotheliomas cells and not found in healthy cells. Choice D says that in some small cases of mesotheliomas there was no exposure to asbestos. This proves that asbestos is not the only cause of the cancer, and in turn strengthens the conclusion that SV40 virus is the cause of the cancer in these cases.

a. is irrelevant
b. irrelevant
c. traces of the virus found shows that vaccines was comtaminated, but does not strengthen the conclusion that the SV40 virus causes cancer. vaccine here is general, not specific to polio. Thus can not apply.
e. This weakens the conclusion. This particular fact shows that where polio vaccine is absent of SV40 virus, mesotheliomas contains no SV40. Thus in this case, SV40 is not the cause of the cancer. This finding weakens the researchers' hypothesis.

I would go for E.
The hypothesis says that the vaccine was the source of the virus found in mesotheliomas decades later.
E strengthens it by illustrating a case where the polio vaccine was not contaminated and mesotheliomas samples did not contain the virus.
D doesn't seem to have a relationship with the hypothesis.

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Re: Although exposure to asbestos is the primary cause of [#permalink]

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12 Dec 2007, 01:47
but guys, what makes E better than C? in C, if the vaccine already shows traces of the virus (and when they mention virus, they are talking about SV40, no?), isn't that good enough? if i understood this text correctly, the reserchers hypothesized that the vaccine was the source of the spread of the virus, so if we can pick an answer choice that shows that the vacines do contain such virus, doesn't that accomplish the task? in option E, that would strengthen the point that the vaccine is not the cause.....hmm....can somebody explain why E is better than C?

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Re: Although exposure to asbestos is the primary cause of [#permalink]

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12 Dec 2007, 02:09
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tarek99 wrote:
but guys, what makes E better than C? in C, if the vaccine already shows traces of the virus (and when they mention virus, they are talking about SV40, no?), isn't that good enough? if i understood this text correctly, the reserchers hypothesized that the vaccine was the source of the spread of the virus, so if we can pick an answer choice that shows that the vacines do contain such virus, doesn't that accomplish the task? in option E, that would strengthen the point that the vaccine is not the cause.....hmm....can somebody explain why E is better than C?

C supports the idea that "polio vaccine was contaminated with the virus" (even though, it is not asked to support this statement) but it does bot support the hypothesis that this vaccine was the source.

though, i don't like E, it's the best choice among all

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Re: Although exposure to asbestos is the primary cause of [#permalink]

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12 Dec 2007, 04:26
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ok i get it! the researchers' hypothesized that SV40 is the cause of mesotheliomas, a type of cancer. And because they found the virus in vaccines, this is why they claim that the vaccine must be the source. In option C, it is true that the vaccine is contaminated, therefore could be the cause, but this option does not isolate for us exactly whether it's the vaccine itself that is causing mesotheliomas or whether SV40 in the vaccine is causing mesotheliomas . remember, the researchers concluded that the vaccine must be the reason ONLY because they found traces of the SV40 in the contaminated vaccine, implying that the vaccine by itself is not the cause, but because of the SV40 that is found in the vaccine. In order to prove that that is the case, we need to find an answer choice with the same vaccine, only that this vaccine is not contaminated with SV40 in order to see whether it will still result in mesotheliomas . in option E, by showing that the same vaccine that is not contaminated with SV40 still doesn't produce mesotheliomas , it strengthens the researchers' hypothesis that it's the SV40 itself that is causing mesotheliomas, a type of cancer.

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Re: Although exposure to asbestos is the primary cause of [#permalink]

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13 Dec 2007, 03:36
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After taking ample time on this question, I have got the option E.

Although exposure to asbestos is the primary cause of mesothelioma, a slow-developing cancer, researches believe that infection by the SV40 virus is a contributing cause, since in the United States 60 percent of tissue samples from mesotheliomas, but none from healthy tissue, contain SV40. SV40 is a monkey virus; however, in 1960 some polio vaccine was contaminated with the virus. Reseaches hypothesize that this vaccine was the source of the virus found in mesotheliomas decades later.

Which of the following, if true, most strongly supports the researchers' hypothesis?

a) SV40 is widely used as a research tool in cancer laboratores.

b) Changes in the technique of manufacturing the vaccine now prevent contamination with SV40.

c) Recently discovered samples of the vaccine dating from 1960 still show traces of the virus.
The bolded part is already saying about contamination so, C will not be the strongest point.
d) In a small percentage of cases of mesothelioma, there is no history of exposure to asbestos.

e) In Finland, where the polio vaccine was never contaminated, samples from mesotheliomas do not contain SV40.
E amplifies the certainty of choice. E also supports the posibility where polio vaccine has never contaminated.

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Re: Although exposure to asbestos is the primary cause of [#permalink]

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23 Dec 2007, 15:15
Hi guys, the OA is E.

I had C for the answer, but clearly, the passage designed to misdirect the reader with "cause" vs "source".

The whole passage concentrated on the "cause" of cancer, but the last sentence mentioned "source". I think many people assumed that the question is asking for the cause. Clearly a sneaky way of asking a question. In the real world, this would be a "gotcha" question being posed by smart alecs, not to be taken seriously.

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Re: Although exposure to asbestos is the primary cause for [#permalink]

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12 May 2010, 15:31
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iamseer wrote:
How did you eliminate C? And why is E the answer?

Other posts on MGMAT forum and this forum say that C states something we already know. I disagree.
the reasoning is:
Yes, we know vaccine was contaminated. But whether it could have an effect 40-50 years down the line is not known. So, knowing that those vaccine still have traces of SV40 gives a subtle new information that the virus can actually survive 40-50 years. So, it strengthens the hypotheses.

vaccine was contaminated with virus SV40 in 1960 ---> (Virus is still present in those vaccine samples of 1960 i.e. virus can survive 40-50 years) ---> vaccine is the source of virus found in cancer tissue.

To make things clear I tried to form an analogy:

Now, if we have to strengthen this hypothesis and 2 options are:

1. In a recent interview David mentioned that he remembers what he had read in that book.
2. Tom who never read the book, could not answer the question.

which one of the option would one choose?

Analogy:
David - Polio vaccine of US
Tom - Polio vaccine of Finland
Reading the book - contamination by virus
answering the question in quiz - virus in mesotheliomas
mentioned that he remembers - still show traces

Wow. That's a long post. I threw out C right away and will try to explain why, but I can tell you are quite passionate about the answer so I may fail in convincing you. Here it goes.

Time that goes by has little to do with this argument. This excerpt could be referring to people with the from the 1960s, or people today. Also, in the first sentence, it says that it’s a “slow-developing cancer.” If infected in 1960, the virus could slowly develop and show up later. Also, it never says anything about when people contracted the cancer. So I have to agree with the OE that C is stating something that we already knew, that the vaccines were infected and that it’s slow developing.

E is a hard reach for me, but it’s the best answer from what there is to choose from. A better choice (not given) would have said something about people that got the cancer were vaccinated for polio in 1960. But unfortunately there is no write in option on the GMAT.

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Re: Although exposure to asbestos is the primary cause for [#permalink]

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12 May 2010, 21:20
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thanks for reading the long post and replying back promptly and objectively.

And yes, you got it right. I am passionate about the answer option but only to the extent of it's logical worth.

Even I threw out C traversing from top to bottom. But on reaching E all options were eliminated So went back to find something.

E looked far fetched b'cos it says effect is absent and cause is absent too. Couldn't quite grasp, how absence of cause and effect, strengthen that cause-effect relationship.

But you are right, E is the best of all choices available. It does increase the chances that vaccine might be the source of virus.

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Re: Although exposure to asbestos is the primary cause of [#permalink]

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19 Jul 2011, 02:30
tarek99 wrote:
ok i get it! the researchers' hypothesized that SV40 is the cause of mesotheliomas, a type of cancer. And because they found the virus in vaccines, this is why they claim that the vaccine must be the source. In option C, it is true that the vaccine is contaminated, therefore could be the cause, but this option does not isolate for us exactly whether it's the vaccine itself that is causing mesotheliomas or whether SV40 in the vaccine is causing mesotheliomas . remember, the researchers concluded that the vaccine must be the reason ONLY because they found traces of the SV40 in the contaminated vaccine, implying that the vaccine by itself is not the cause, but because of the SV40 that is found in the vaccine. In order to prove that that is the case, we need to find an answer choice with the same vaccine, only that this vaccine is not contaminated with SV40 in order to see whether it will still result in mesotheliomas . in option E, by showing that the same vaccine that is not contaminated with SV40 still doesn't produce mesotheliomas , it strengthens the researchers' hypothesis that it's the SV40 itself that is causing mesotheliomas, a type of cancer.

Option c says :

Recently discovered samples of the vaccine dating from 1960 still show the virus....

referring to the quoted bolded part : Over here virus means SV40 since in the passage it is stated ...sv40 is a virus... so Why is C still wrong then..

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Re: Although exposure to asbestos is the primary cause of [#permalink]

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20 Jul 2011, 21:41
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Asbestos is primary cause for mesothelioma.
SV40 is a contributor as a percentage of tissue was found with the virus in mesothelioma cases.
Some polio vaccine was contaminated with SV40.
Hypothesis: Vaccine was source of virus found in mesothelioma.

What supports the hypothesis?
A - Unrelated
B - Unrelated
C - Reiterates/restates that some vaccine was indeed conaminated, but doesn't help prove the vaccine was the source of the virus found in mesotheliomas.
D - Reiterates/restates that although asbestos is a primary cause, SV40 is a contributor.
E - US had contamination, and subsequently, SV40. Finland had no contamination, and we hypothesize, no SV40 as a result. This helps our overall hypothesis that the contaminated vaccine was the source of the virus. This is the correct answer.

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Re: Although exposure to asbestos is the primary cause of [#permalink]

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27 Sep 2011, 21:50
E for me:

1) May be So what . OOS
2) Ok true. But OOS
3) may be showing: but does that leads to cancer?? dont know
4) Small %: support very little
5) Strongly suports by taking a case study of finland.

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11 Nov 2011, 09:32
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Re: Although exposure to asbestos is the primary cause for [#permalink]

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12 Nov 2011, 07:31
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Phew... After a big dilema between E and C went with C.

But E wins. Though not convinced much, but will take the causal effect relationship route.

Researchers hypothesize that vaccine -> virus in tissue.

Option E eliminates the possibility of the event happening even when the cause doesn't occur. (Power score route )
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Re: Although exposure to asbestos is the primary cause for [#permalink]

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17 Jan 2012, 10:12
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Practicegmat wrote:
not yet convinced with E ... Could anyone elaborately explain why E is the correct answer ?

Thanks

First let us understand what the argument is about. All that is hypothesized is THE SOURCE OF virus; the argument does NOT INTEND to verify if the virus IS ALSO causing the cancer: it is just taken for granted (i.e., the virus can also contribute) and we can safely ignore it for the discussion.

Now, we need to prove that there is a possibility that the virus could have been due to contaminated vaccine.

We have 3 sets of people:

--> In US, two sets of people: ill people with contaminated vaccine + a virus and healthy people with clean vaccine + NO VIRUS.
--> In Finland, one set of people: ill people with clean vaccine + NO VIRUS.

from those 2 premises, we can conclude that the virus is due to contaminated vaccine and this is exactly what researchers hypothesized in the last sentence.

Note: there could be some other reason for the virus presence, but in the given context we can not eliminate the possibility of contaminated vaccine.

A very good question. Got confused for a some time.

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Re: Although exposure to asbestos is the primary cause of [#permalink]

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26 May 2012, 10:38
tarek99 wrote:
Although exposure to asbestos is the primary cause of mesothelioma, a slow-developing cancer, researches believe that infection by the SV40 virus is a contributing cause, since in the United States 60 percent of tissue samples from mesotheliomas, but none from healthy tissue, contain SV40. SV40 is a monkey virus; however, in 1960 some polio vaccine was contaminated with the virus. Reseaches hypothesize that this vaccine was the source of the virus found in mesotheliomas decades later.

Which of the following, if true, most strongly supports the researchers' hypothesis?

a) SV40 is widely used as a research tool in cancer laboratores.

b) Changes in the technique of manufacturing the vaccine now prevent contamination with SV40.

c) Recently discovered samples of the vaccine dating from 1960 still show traces of the virus.

d) In a small percentage of cases of mesothelioma, there is no history of exposure to asbestos.

e) In Finland, where the polio vaccine was never contaminated, samples from mesotheliomas do not contain SV40.

If you're deciding between (C) and (E) - you'll have to understand which one MORE strengthens the argument.

(C) provides a statement that supports an existing assumption. It supports the fact that there was contamination in 1960. However, it doesn't affect the link between the assumption and the argument.

You can think of it as:
--Argument
--Assumption
--Statement (C)

Where (C) supports the assumption - but the link between assumption and argument is not really strengthened. If any, it is strengthened slightly by a small amount since the assumption is stronger/more valid.

With (E), this is GMATPill's A vs Not A Framework.
The passage is making the argument that contamination in 1960 leads to the "hypothesis" vaccine was the source of the virus in mesothelioma years later.
The framework tells us that if we can establish a relationship for the opposite state leading to the opposite conclusion, then that relationship is good enough to establish support for our original assumption->argument.
So here, that opposite relationship is established.

In Finland where polio vaccination was NOT contaminated, samples from mesotheliomas do NOT contain SV40.

If this is the opposite relationship that is established, the original relationship must be:
Where polio vaccination WAS contaminated, samples from mesotheliomas DID contain SV40 - which is what the passage is saying.

So since the opposite relationship is established in (E), we know our assumption->argument is supported.

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Re: Although exposure to asbestos is the primary cause of [#permalink]

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07 Jun 2012, 03:52
a) SV40 is widely used as a research tool in cancer laboratores. - Irrelevant information - Incorrect
b) Changes in the technique of manufacturing the vaccine now prevent contamination with SV40. - We are talking about the vaccines that have been contaminated rather than the technique of manufacturing or the present scenario of the vaccine - Irrelevant information - Incorrect
c) Recently discovered samples of the vaccine dating from 1960 still show traces of the virus. - It has already been mentioned in the premise that 1960 samples of vaccine have been contaminated by SV40 virus - Nither supports nor rejects - Incorrect
d) In a small percentage of cases of mesothelioma, there is no history of exposure to asbestos. - This takes a neutral stand and does not mention about SV40 virus in any case - Incorrect
e) In Finland, where the polio vaccine was never contaminated, samples from mesotheliomas do not contain SV40. - Vaccine that was never contaminated with SV40 in Finland and it was found that mesotheliomas did not contain SV40. Hence it proves the hypothesis - Correct

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Re: Although exposure to asbestos is the primary cause for [#permalink]

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07 Jan 2013, 06:58
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iamseer wrote:
Although exposure to asbestos is the primary cause for mesothelioma, a slow-developing cancer, researchers believe that infection by the SV40 virus is a contributing case, since in the US 60 percent of tissue samples from mesotheliomas, but none from healthy tissue, contain SV40. SV40 is a monkey virus; however, in 1960 some polio vaccine was contaminated with the virus. Researchers hypothesize that this vaccine was the source of the virus found in mesotheliomas decades later.

Which of the following, if true, most strongly supports the researchers' hypothesis?

A) SV40 is widely used as a research toll in cancer laboratories.
B) Changes in the technique of manufacturing the vaccine now prevent contamination with SV40
C) Recently discovered samples of the vaccine dating from 1960 still show traces of the virus.
D) In a small percentage of cases of mesothelioma, there is no history of exposure to asbestos.
E) In Finland, where the polio vaccine was never contaminated, samples from mesotheliomas do not contain SV40

We need something that helps that it is the virus from the vaccine.
We already know the vaccine is contaminated.

A. This does nothing to help the argument. out!
B. this is great news but what about the contaminated vaccine and the infected sample tissue. This is our concern. Out!
C. Contaminated vaccine is not sufficient to prove that the virus in the tissue was transmitted from the vaccine. We already know vaccines are contaminated. We need evidence that the tissues were infected through the vaccine.
D. This only proves that it is not the asbestos. But doesn't add to vaccine infecting tissue. Out!
E. this is it! Another vaccine without contamination and tissue samples without virus... This is a good additional evidence. Although it is not full proof, it helps.

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Re: Although exposure to asbestos is the primary cause of [#permalink]

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20 Mar 2013, 11:38
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tarek99 wrote:
Although exposure to asbestos is the primary cause of mesothelioma, a slow-developing cancer, researches believe that infection by the SV40 virus is a contributing cause, since in the United States 60 percent of tissue samples from mesotheliomas, but none from healthy tissue, contain SV40. SV40 is a monkey virus; however, in 1960 some polio vaccine was contaminated with the virus. Reseaches hypothesize that this vaccine was the source of the virus found in mesotheliomas decades later.

Which of the following, if true, most strongly supports the researchers' hypothesis?
(A) SV40 is widely used as a research tool in cancer laboratores.
(B) Changes in the technique of manufacturing the vaccine now prevent contamination with SV40.
(C) Recently discovered samples of the vaccine dating from 1960 still show traces of the virus.
(D) In a small percentage of cases of mesothelioma, there is no history of exposure to asbestos.
(E) In Finland, where the polio vaccine was never contaminated, samples from mesotheliomas do not contain SV40.

fameatop wrote:
I am not able to understand why option C is incorrect & E is correct. Can you kindly throw some light on the same. Waiting eagerly for your detailed explanation. Regards, Fame

Fame,
So, the argument presents, as evidence, the fact that "in 1960 some polio vaccine was contaminated with the virus." That's evidence, so for GMAT purposes, that's fact beyond dispute. Then it makes the argument, the hypothesis, that SV40 in the vaccine CAUSED the SV40 in the mesotheliomas. That's the actual argument we are trying to support, the link between the SV40 in the vaccine and the SV40 in the mesothelioma tissue.

Well, (C) merely strengthens the evidence. We already were told that there was SV40 virus in the polio vaccine. That's already beyond doubt. Statement (C) strengthens this statement that is already beyond doubt, but it doesn't say squat about the link to mesothelioma. The researchers were hypothesizing this link between SV40 virus in the vaccines and mesothelioma, and (C), while it verifies --- "yep, there sure was SV40 in that polio vaccine!" --- doesn't bring us any closer to a link with with mesothelioma. The argument is all about that link.

By contrast, (E) is very powerful. If the SV40 virus in the vaccines really is the source of the virus in the mesothelioma tissue, then if we found some case in which there was no SV40 virus in the vaccine, then we would expect to find no SV40 virus in the mesothelioma tissue. (E) provides this new and very cogent evidence. This is new, different from what was stated in the passage, although it provides strong support to the passage. In general, if I make the argument that P and only P causes Q, then part of what I am predicting is --- if there's no P, then there should be no Q. That would be very powerful evidence for this claim, and this is precisely the nature of the powerful evidence that (E) provides. That's why it's the best answer.

Does this make sense?

Mike
_________________

Mike McGarry
Magoosh Test Prep

Kudos [?]: 8432 [1], given: 102

Re: Although exposure to asbestos is the primary cause of   [#permalink] 20 Mar 2013, 11:38

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