The number of United States citizens suffering from the flu increased

+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.

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

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

C

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

C is a clear choice.

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