The correct answer is it divides power between the federal government and the state and local governments.
This concept is known as a separation of powers. This separation of powers is evident in the Bill of Rights. The 10th amendment states that any power not given directly to the federal government or denied to the state governments, belongs to the state itself. This gives states over control of several different elements including things like education, sales tax, etc. This ensures that no one government entity gains too much power in American society.