请教PP一阅读

Formal organizations can be grouped into three

broad types.  Some organizations are voluntary

organizations ---people choose to join them because

they are interested in the group's purpose or

activities.  Examples of voluntary organizations are

political groups and professional organizations.  

Another type, overlapping somewhat with voluntary

organizations, is the utilitarian organization --- an

organization designed to accomplish some task.  

Businesses and neighborhood improvement

associations are examples of this type, as are

large-scale organizations such as governments

and corporations.  Finally, there are coercive

organizations---organizations that people are

compelled to participate in, such as the military in

some countries.  Children frequently participate in, a

wider range of coercive organizations, most notably

schools.

99. Which of the following statements is

   best supported by the passage?

   AThere are more people in

      voluntary organizations than

      in political groups.  

   BChildren participate in a

      greater number of coercive

      organizations than do adults.  

   CAdults are trying to get children

      more involved in utilitarian

      organizations.  

    DMore people are interested in

      political organizations than in

      professional groups.  

答案是B,为什么A不对呀？

文中说：Examples of voluntary organizations are political groups and professional organizations.  那不是就是说political groups 是属于voluntary organizations 的吗？那不就是There are more people in  voluntary organizations than in political groups吗？

谢谢