The secret police formed by Hitler to operate within Germany were known as the "SS', although the responsibilities of the SS soon spread to more than just domestic policing. <span />
It provided the philosophical underpinnings that is reflected in the Declaration of Independence.
Statements A. C. and D. are all actions that individuals/groups can take that affect government policies.
The ability to petition and assemble (mentioned in statements A and D) are two of the five freedoms guaranteed in the first amendment of the US Constitution. These actions, as long as they are peaceful, can help to bring awareness to issues that citizens find relevant.
Lobbying is another action citizens can take. This can include writing letters, asking for interviews, and developing deals. All of these actions can result in change of government policies.