Those who participate in local politics include people who are genuine

Those who participate in local politics include people who are genuinely interested in public service and people who are selfish opportunists. Everyone who participates in local politics has an influence on the community’s values.

Participants in local politics = Interested in public service + Selfish people + X type + Y type + .....
All participants have influence.

(A) Some selfish opportunists have an influence on the community’s values.
Some have an influence, hence must be true

(B) Some persons who are interested in public service do not have an influence on the community’s values.
Not sure if ALL members of the group of people interested in public service are involved in local politics.

(C) All those who have an influence on the community’s values participate in local politics.
Cannot say that for certain, there might be others who ALSO have influence (in addition to the ones participating)

(D) Some of those who influence the community’s values neither are interested in public service nor are selfish opportunists.
We do not know for certain. This is true if only 2 groups as stated in the passage exists. If there are more groups, then this statement is not true.

(E) All those who have an influence on the community’s values are either interested in public service or are selfish opportunists.
Again not true. There may be yet others who have an influence but belong to another group (apart from the 2 stated in the passage).

It could also happen that none of the selfish opportunists participate in local politics. In that case, how will they have an influence on the community’s values? Help me understand, how A is correct?

I am happy to answer your doubt.

The first statement is - "Those who participate in local politics include people who are genuinely interested in public service and people who are selfish opportunists."

Which means participants include a) interested in public service, b) selfish, c) others

It is explicitly stated that there is AT LEAST 1 selfish guy who participates.

For statement D, This will be true only when there are more than two groups, which is why this is not the correct option. Is my understanding correct?

Those who participate in local politics include people who are genuinely interested in public service and people who are selfish opportunists. Everyone who participates in local politics has an influence on the community’s values.

If the statements above are true, which one of the following must also be true?

Participation in Local Politics - PLP
People with interest in Public Service - PIPS
People who are Self Opportunists - PSO
Influence on the Community's Values - ICV

PIPS / PSO ----> PLP ----> ICV

Hence following reverse relations are Not possible:
1. ICV ----> PIPS / PSO
2. n PIPS / nPSO ----> nICV
3. nICV ----> nPIPS / nPSO
4. PIPS / PSO ----> nICV
5. ICV ----> nPIPS / nPSO

Additionally, the scale(percentage of people) plays another variability aspect of the possibilities.

(A) Some selfish opportunists have an influence on the community’s values. - CORRECT.

(B) Some persons who are interested in public service do not have an influence on the community’s values. - WRONG. Case 4

(C) All those who have an influence on the community’s values participate in local politics. - WRONG. Not covered in the four possibilities but 'all' must not be possibile.

(D) Some of those who influence the community’s values neither are interested in public service nor are selfish opportunists. - WRONG. Case 5.

(E) All those who have an influence on the community’s values are either interested in public service or are selfish opportunists. - WRONG. Case 1.

Answer A.