B. But the most important thing you can do is to get to know as many people as you can in your community, because your friends and neighbors may well become your greatest supporters.
Explanation:
The selection that best supports the central idea that getting involved with politics can be a fun and rewarding way to make a difference in your community is selection B. In this passage, meeting new people is mentioned. Friends are something we associate with fun, and running for office with their support could be an interesting experience.
The rest of the options lack this element of fun. They simply mention improving people's lives, different positions you can run for, and how hard you should work in order to run a successful political campaign. This is why option B is the correct one.
