Hi Kappe,
Let's start with why E is wrong.
E states that ALL who have an influence on the community values are either interested in public service or a selfish opportunist.
However, the stimulus looks like this:
participate in local politics

interested in public service
participate in local politics

selfish opportunist
We know that these two are only *some* because of the word "include" in the stimulus. There could be people who are neither interested in public service or are selfish opportunists who participate in local politics.
Finally:
Participate in local politics

influence on values
E does not follow. The "all" in the answer choice makes the answer wrong: only
some people who participate in local politics are either a selfish opportunist or interested in public service.
Answer choice A is correct.
Some selfish opportunists (namely those that participate in local politics) has an influence on community values (everyone who participates in local politics has such an influence).
I hope that helps!