The number of United States citizens suffering from the flu increased

Question

The number of United States citizens suffering from the flu increased significantly this year over last year. Since this increase did not occur among citizens of other countries, it is likely the result of a particular flu virus confined to the United States.

Which of the following, if true, would cast the most serious doubt on the explanation for the increase given above?

A. Many non-US citizens took flu vaccines this year.

B. This year, the flu suffered by citizens of other countries was generally more severe than that suffered by US citizens.

C. A large percentage of US citizens who suffered from the flu this year were living abroad.

D. Many US citizens who suffered from the flu this year also suffered from the flu last year.

E. The number of US citizens did not change significantly between last year and this year.

pkshankar · Answer

'C' is the answer.
'C' strengthens the idea that the fact that U.S. citizens are down with flu doesn't really mean that the virus is confined to the U.S.

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sudarshan22 · Answer

+1 for   C  .

C. A large percentage of US citizens who suffered from the flu this year were living abroad. -->   Correct , weakens the conclusion by stating that the flu is confined in other countries, but in the US

Hence,   C  .

GmatDaddy · Answer

The number of United States citizens suffering from the flu increased significantly this year over last year. Since this increase did not occur among citizens of other countries, it is likely the result of a particular flu virus confined to the United States.

Which of the following, if true, would cast the most serious doubt on the explanation for the increase given above?

A. Many non-US citizens took flu vaccines this year.  Doesnt help with conclusion. Discard

B. This year, the flu suffered by citizens of other countries was generally more severe than that suffered by US citizens.  Argument is regarding numbers of flu infected US citizens and the conclusion is regarding confines of flu virus. This doesnt help Discard

C. A large percentage of US citizens who suffered from the flu this year were living abroad.  Bingo! Rips the conclusion to shreds! US citizens suffering from the flu were living outside of US

D. Many US citizens who suffered from the flu this year also suffered from the flu last year.  Doesn't weaken our Conclusion. Discard

E. The number of US citizens did not change significantly between last year and this year.  This doesn't help either. Discard

Skywalker18 · Answer

The number of United States citizens suffering from the flu increased significantly this year over last year. Since this increase did not occur among citizens of other countries, it is likely the result of a particular flu virus confined to the United States.

Type- weaken
Boil it down- Since this increase did not occur among citizens of other countries, it is likely the result of a particular flu virus  confined  to the United States.

A. Many non-US citizens took flu vaccines this year. - Irrelevant

B. This year, the flu suffered by citizens of other countries was generally more severe than that suffered by US citizens. - Irrelevant - the severity of the flu isn't relevant

C. A large percentage of US citizens who suffered from the flu this year were living abroad. - Correct - If this is true, then we can't say that the particular flu virus was confined to the united states

D. Many US citizens who suffered from the flu this year also suffered from the flu last year. - Irrelevant

E. The number of US citizens did not change significantly between last year and this year. - Irrelevant

Answer C

LeoGT · Answer

Fact  :  The number of United States citizens suffering from the flu increased significantly this year over last year
   Evidence   : this increase did not occur among citizens of other countries
   Conclution  :  it is likely the result of a particular flu virus confined to the United States

This is a weak argument. Author want to drive testtakers to the way that the number of people suffering from flu not increase, so cannot be the reason of other increase. But from "Not increase" to cannot be reason" needs a big assumption.
   Analogy   
Average GMAT score of class A is increased from this to last year. 
This increase does not happen with other class.
Conclution: this increase is the result of students in class A
There can be case that average of other class is 800, cannot be higher. And students in class A learn alot from other class.

Back to question, C break the argument. People bring flu from abroad to country.

Mittali · Answer

C

Since the large % of people were living abroad this means the flu was not confined to the US

jackspire · Answer

C is a clear choice.

ArvindS37 · Answer

B. This year, the flu suffered by citizens of other countries was generally more severe than that suffered by US citizens.
This choice shows that flu is present in other countries as well as in US. Thus, flu is not confined to US. This can be weakner.
But here, we are talking about particular flu that is confine to US. As, this choice doesn't talk about this  particulat flu confined to US that leads to increase in number of cases in US. this choice doesnt affect the conclusion.

Thus, in between C and B, C is clearly a better option.

Abhishek_007 · Answer

Premise  : The number of U.S. citizens suffering from the flu increased significantly this year over last year.
 Additional Premise  : This increase did not occur among citizens of other countries.
 Conclusion  : The increase is likely due to a particular flu virus confined to the United States.

Answer  : (C) A large percentage of US citizens who suffered from the flu this year were living abroad.

Becuase, this directly undermines the assumption of geographical confinement.

VerbalBot · Answer

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The number of United States citizens suffering from the flu increased

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The number of United States citizens suffering from the flu increased

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