Answer:
The correct answer is D: interest groups usually attempt to influence policy makers and the public to support policies that benefit a particular industry or group.
Step-by-step explanation:
Interest groups are groups of people acting united in order to influence the making of public policies. There are many ways for doing that. For example, a group of environmentalists may try to impact an environmental public policy by spreading to the general public recent numbers about deforestation and realizing private meetings with policymakers in Congress.
Answers A and C are only specific cases of interest groups' political action that can't be generalized for all interest groups. They are incomplete answers.
Answer B is wrong because informing the voters is only one of the actions that interest groups do. Option D is a more complete answer.