The correct answer is federal, state and local governments.
All three levels of government are limited in what they can do. For example, Congress is limited in terms of what laws they can make. Congress can make no law that will take away an individuals freedoms (like freedom of religion, freedom of press, etc.). All other levels of government are the same way.
Along with this, popular sovereignty is used at all levels of the government. Popular sovereignty is based on the idea of majority rule. Simply put, the person with the most votes wins. This concept is how we vote for mayors, senators, and other political figures in the US.