Questions: The Founders of the United States believed in protecting freedoms for all citizens because of the Enlightenment idea of: A. separation of powers. B. natural rights. C. popular sovereignty. D. the social contract.

The answer is B. natural rights.

The concept of separation of powers, advocated by Enlightenment thinkers like Montesquieu, refers to dividing government responsibilities into distinct branches to prevent any one branch from gaining too much power. While important, it is not directly related to the protection of individual freedoms.

The Enlightenment idea of natural rights, as articulated by philosophers like John Locke, posits that individuals inherently possess rights such as life, liberty, and property. The Founders of the United States were heavily influenced by this concept, which is evident in the Declaration of Independence's assertion of "unalienable Rights" including "Life, Liberty and the pursuit of Happiness."

Popular sovereignty is the principle that the authority of a state and its government are created and sustained by the consent of its people, through their elected representatives. While it is a foundational concept for democratic governance, it is not specifically focused on individual freedoms.

The social contract theory, associated with thinkers like Rousseau and Hobbes, suggests that individuals consent, either explicitly or implicitly, to surrender some of their freedoms and submit to the authority of the ruler or magistrate in exchange for protection of their remaining rights. While related to governance and rights, it is not as directly focused on the protection of individual freedoms as the concept of natural rights.