Answer:
c. interest group
Explanation:
An interest group refers to a group of people(or even organizations) who associate together in a formal way and that attempts to influence public policy in its favour. In other words, they are a group of people who share a common interest and that gather together in a formal way to get benefits by influencing public policies.
The main goal of these groups is to influence the people who make decisions to be benefitted by these decisions.
Therefore, A group of citizens with common interests who try to influence public policy to benefit its members is called an interest group.