In the Three Broad Categories of Reasons Why Individuals Join

In the three broad categories of reasons why individuals join interest groups, the category of solidary benefits refers to the ___ .

A) real and tangible benefits, like lower taxes, lighter regulation, higher wages, and group insurance rates
B) substantive, partisan, and ideological goals, like fighting hunger, supporting Republicans, or battling socialists
C) simple joys and social rewards of meeting, getting to know, and working with like-minded people
D) None of the above