Which of the following is NOT a branch of the United States government?

The administrative branch is not recognized as an official branch of the United States government. The U.S. government is structured into three primary branches, which are the legislative, judicial, and executive branches.

The legislative branch, composed of Congress (the House of Representatives and the Senate), is responsible for making laws. The judicial branch interprets those laws and is comprised of the court system, including the Supreme Court. The executive branch, led by the President, is responsible for enforcing the laws enacted by Congress.

The term "administrative" can sometimes refer to certain functions or agencies within the executive branch, but it does not denote a separate or official branch. Therefore, identifying this option distinguishes it from the other three, which are explicitly defined in the U.S. Constitution. This understanding of the branches is fundamental in grasping the structure and functioning of the U.S. government.