Which of the following is NOT a cabinet-level department in the executive branch?

The Environmental Protection Agency (EPA) is indeed not a cabinet-level department in the executive branch, while the other options listed—Treasury, Labor, and Interior—are recognized as cabinet-level departments. The EPA, established later than the main cabinet departments, operates as an independent agency, which means it has a specific mandate focused on environmental protection and regulation, but it does not have the same status as the traditional cabinet departments. These cabinet departments, created to address broader areas of governance and public policy, are headed by secretaries who are members of the president's cabinet, directly advising the president and partaking in high-level decisions of federal administration. Understanding this distinction is key to grasping the structure and functions of the U.S. government.