The correct answer is A. To influence government policy
Step-by-step explanation:
An interest group refers to a group of individuals that organize for a common cause that is usually related to public policy; indeed most interest groups aim at supporting or opposing a policy or to make people aware of this without directly opposing the government or trying to make his members part of it as in political parties. Additionally, interest groups used multiple strategies such as publicity, campaigns or research to achieve their purposes. Considering this, it can be concluded the main purpose of an interest group is to influence government policy.