Which branch enforces laws in the American government system?

The correct choice is the executive branch, which is responsible for enforcing laws within the American government system. The executive branch, led by the president, ensures that the laws passed by the legislative branch are implemented and followed. This branch includes various federal and state agencies that manage the execution of laws and policies, handling day-to-day enforcement and administration.

While the judicial branch interprets laws and resolves disputes related to their application, and the legislative branch is responsible for creating laws, it is the executive branch that holds the duty to enforce those laws. The term "judiciary," although often used interchangeably with the judicial branch, specifically refers to the court system and judges within the judicial branch, further emphasizing the separation of powers where enforcement is clearly a function of the executive.