The main purpose of political action committees (PAC’s) is to obtain con-

tributions of money from individuals for the electoral campaigns of political

candidates.  By increasing the number of their contributors, PAC’s get

more people interested in the political process.  Those who doubt this

claim need only bet $50   the next time they go to the horse races: they will

see how much more interested they are than when they bet nothing.

 A  The argument depends on which of the following assumptions?

       Individuals who contribute money to PAC’s generally give no more

        than  $50  during any particular political campaign season. 

     B  Many people who contribute money to PAC’s usually also bet fairly

        heavily when they go to the horse races or other sporting events. 

   C    Among the people who contribute money to PAC’s are individuals who

        would not have become interested in the political process at that time

        if they had not contributed money to a PAC. 

     D E   Those people who are interested in the political process come from a

        narrowly defined portion of the population at large. 

      Those people who contribute to more than one PAC have no stronger

        interest in the political process than those people who contribute to

        only a single PAC. 

答案：C