Name one branch or part of the government.

Congress is correctly identified as one branch of the U.S. government. It is part of the legislative branch, which is responsible for making laws. The legislative branch, along with the executive and judicial branches, forms the core structure of the federal government as established by the U.S. Constitution.

The other choices represent organizations or entities that do not fit the definition of a branch of the government. For example, the Federal Bureau of Investigation (FBI) is a part of the executive branch, focused on federal law enforcement. The World Health Organization and the United Nations are international organizations that deal with global health and diplomacy, respectively, and are not branches of the U.S. government.