The correct answer is citizens participating in the law making process.
In the United States, citizens have a voice in the law making process. At the federal (national level) citizens vote on officials who will make laws for the entire country. On a state level, citizens sometimes have the opportunity to vote on laws/amendments to state constitutions.
This process allows citizens to voice their concerns and desires. This system revolves around the idea that the citizens have ultimate control over what new laws are implemented in America.