What does FBI stand for?

The correct answer is the Federal Bureau of Investigation. This is the primary federal investigative agency and domestic intelligence service of the United States. It operates under the Department of Justice and is tasked with investigating violations of federal law, maintaining national security, protecting civil rights, and conducting various security operations across the country. The FBI is well-known for its role in criminal investigations, counterterrorism efforts, and cybercrime initiatives, making it a crucial component of the U.S. law enforcement landscape.

Other options do not accurately reflect the established name or functions of this agency. The terms "Internal Affairs," "Intelligence," and "Identification" do not correspond to the correct operational scope or legal framework of the FBI, which has developed a specific identity tied to its actual responsibilities and historical context.