Hepatits A

neoreaves wrote:The symptoms of hepatitis A appear no earlier than 60 days after a person has been infected. In a test of hepatitis A vaccince, 50 people received the vaccine and 50 people received harmless placebo. Although some people from each group eventually exhibited symptoms of hepatitis A, the vaccine as used in the test is completely effective in preventing infection with the hepatitis A virus.

WHich one of the following, if true, most helps resolve the apparent discrepancy in the information above?

A) The placebo did not produce any side effects that resembled any of the symptoms of hepatitis A.

B) More members of the group that had received the placebo recognized thier symptoms as symptoms of hepatitis A than di members of the group that had received the vaccine.

C) The people who received the placebo were in better overall physical condition than were the people who received the vaccine.

D) The vaccinated people who exhibited symptoms of hepatitis A were infected with the hepatitis A virus before being vaccinated

E) Of the people who developed symptoms of hepatitis A, those who received the vaccine recovered more quickly, on average, than those who did not

Source: LSAT PrepTests

OA : D

The discrepancy is over hepatitis A vaccine-- Though the vaccine is good in its work but still vaccinated people have been found suffering from this disease.
It can be explained if we say that there were some poeple who were suffering from hepatitis A and so after vaccine were found to be infected from hepatitis A.
If we go by elimination apporach:
A) The placebo did not produce any side effects that resembled any of the symptoms of hepatitis A..........IRRELEVANT
B) More members of the group that had received the placebo recognized thier symptoms as symptoms of hepatitis A than di members of the group that had received the vaccine.......WE HAVE NOTHING TO DO WITH THE NUMBER OF MEMBERS BUT WITH PEOPLE WHO WERE VACCINED AND WERE FOUND INFECTED FROM HEPATITIS A.
C) The people who received the placebo were in better overall physical condition than were the people who received the vaccine......IRRELEVANT

E) Of the people who developed symptoms of hepatitis A, those who received the vaccine recovered more quickly, on average, than those who did not ........THIS IS ALSO IRRELEVANT AS IT IS SUPPORTING THE POINT THAT THERE WERE PEOPLE WHO WERE ALREADY SUFFERING FROM HEPATITIS A.

so, acc to me D is the ans.

imo d as the symptoms are not visible who has been affected by hepatitis A. so when vaccine is given after that the symptoms were visible.