Which of the following is NOT part of the Department of Defense?

The Department of Transportation is indeed NOT part of the Department of Defense. The Department of Defense (DoD) is a critical executive branch of the U.S. government that is responsible for coordinating and supervising all agencies and functions related to national security and military affairs. It comprises several key components, including the Department of the Army, Department of the Air Force, and Department of the Navy, all of which focus specifically on military operations and defense strategies.

In contrast, the Department of Transportation oversees national transportation systems, including highways, railroads, and air travel, which are unrelated to military functions. This fundamental difference in purpose and function distinguishes it clearly from the components of the Department of Defense. The structure of the DoD is designed specifically for the management of military resources and operations, while the Department of Transportation focuses on the efficacy and safety of transportation systems crucial to civilian infrastructure.