Final answer:
The term referring to each branch of government having its own responsibilities is Separation of Powers. It ensures no single branch becomes too powerful by involving all branches in governance with a system of checks and balances.
Step-by-step explanation:
The term that refers to the idea that each branch of government has its own responsibilities is D) Separation of Powers. This principle was put into place by the Founding Fathers to prevent any one branch from becoming too powerful.
The legislative branch is responsible for making laws, the executive branch for enforcing laws, and the judicial branch for interpreting laws. Together, with a system of checks and balances, these branches work together to govern the nation and ensure the powers are balanced.