Medical researchers discovered that people with an atypical form of di

I've noticed a pattern in such assumption questions.

Premise states: A causes B.

Assumption is B didn't cause A. In all the OG questions I've seen, B didn't Cause A has been the right answer in such questions.

The author here concludes that virus V causes atypical diabetes. Therefore, he assumes that virus V is the only cause of atypical diabetes (according to The GMAT Critical Reasoning Bible). So people not infected with virus V cannot develop atypical diabetes and therefore answer C is also correct.

well the conclusion here is that virus V triggers atypical diabetes. so the assumption must be diabetes cannot trigger the virus.

+1 for D

(but, originally went for C)

After trying to get my head around why C is not correct I think I finally got it. Answer C says "Individuals not infected with virus V cannot develop atypical diabetes" whereas the stimilus says "Medical researchers discovered that people with an atypical form of diabetes " the keyword here is "an" which indicates that this is one of many atypical form of diabetes. C refers to all forms of atypical diabetes

Had i not studied from CR Bible I would've definitely gone for D.....but now I am equally attracted by C.....idk...my CR skills seem to have become more shaky than before......

Please someone explain why C isnt corect according to Powerscore CR bible's methodology.....none of the above explanations convince me.....

Easy to pick C but here is why it is wrong. The argument says "a dispropotionately large number". It doesnt say all people who have atypical diabetes have Virus V. So that rules out C straight away because C suggests that all people who have atypical diabetes have virus V. Now we are just looking to establish that the atypical diabetes does not cause Virus V, it is supposed to be the other way around. Hence the only option that supports that is D.

Hence D.

(C)Individuals not infected with virus V cannot develop atypical diabetes.
(D)Atypical diabetes does not predispose people to infection from virus V.

Two choices I narrowed down to were these.

I tried negating to see which one would affect the argument that Virus led to Atypical diabetes.

C) WHEN NEGATED --> Individuals not infected with virus V can develop atypical diabetes. (Doesn't seem to weaken argument) NOTE: Here one can go wrong if he or she replaces the not infected part. Not infected is not a restricter in the argument and is definitely not the main action in the sentence. Not infected is only a subset, so if you wrongly NEGATED the not infected part then you WILL be confused and you will find it difficult to narrow down further.

D) WHEN NEGATED --> Atypical diabetes predisposes people to infection from virus V. (WEAKENS ARGUMENT because it gives an alternate reason by reversing the causal)

D is correct BUT what is wrong with C. CR bible says

a) eliminate any alternate cause for stated effect (WHICH IS C)
b) show that "EFFECT" does not cause "CAUSE" (WHICH IS D)

The argument says Virus V --> (causes) Diabetes

Assumption:
1. Diabetes does not cause Virus V to come.
2. Since it is of the form X leads to Y, it means an alternate cause will be valid. So, Something else caused diabetes would be correct here.

(A)The longer the length of time an individual is infected with virus V, the greater the risk that individual will develop atypical diabetes. : This is not an assumption but a restatement of the fact.
(B)Atypical diabetes is a symptom of virus V. : We already know this. Not an Assumption.
(C)Individuals not infected with virus V cannot develop atypical diabetes. : Remember the rule: If p--> Q, then It doesn't mean Not p --> Not Q. So, it is Incorrect
(D)Atypical diabetes does not predispose people to infection from virus V. : As per our Pre thinking, Hence, correct
(E)Specialized treatment for virus V infection will be more effective than the standard course of virus V treatment for people with atypical diabetes. Irrelevant

From the question we know X causes Y

D)- Y does not cause X-
For the author to conclude X causes Y. He/She must have assumed that Y does not cause X.In case it does, the conclusion doesn't hold true.

C)- X didn't occur Y cannot occur.
What if Z leads to Y?
We know X causes Y but we don't know that only X causes Y.

Hope this helps.

(A) The longer the length of time an individual is infected with virus V, the greater the risk that individual will develop atypical diabetes.
we are not aware about the fact whether the virus affects immediately or it takes a longer period to create higher infection

(B) Atypical diabetes is a symptom of virus V.
Maybe however there is a possiblity that there can be cases where atypical diabetes was not followed by Virus V infection

(C) Individuals not infected with virus V cannot develop atypical diabetes.
This is nowhere stated in the argument therefore cannot be determined

(D) Atypical diabetes does not predispose people to infection from virus V.
Yees this can be a possiblity that it follows that atypical diabetes doesn't always make the individual suspectible to Virus V

(E) Specialized treatment for virus V infection will be more effective than the standard course of virus V treatment for people with atypical diabetes.
This thoroughly out of context
Hence IMO D

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