Answer:
B) social contract
Step-by-step explanation:
The legitimacy of the U.S. government is based on the theory of social contract.
This theory establishes that humans form governments so that their basic rights are protected, and if these governments are ineffective at protecting these rights, they can be removed.
We can see this principles laid out in the U.S. Constitutions, which states that the government exists to serve the people, and the people have the right and duty to keep track on government's power.