Which of the following is a key principle of the United States Constitution?

Separation of powers is a key principle of the United States Constitution. It refers to the division of governmental authority among three distinct branches: the legislative branch, the executive branch, and the judicial branch. Each branch has its own responsibilities and powers, which are outlined in the Constitution. This system of separation of powers is designed to prevent the concentration of power in one branch and to provide checks and balances to ensure that no single branch becomes too dominant. It is a fundamental principle that helps to safeguard individual rights and maintain the balance of power within the U.S. government.