Which of the following acronyms refers to a regulatory body associated with naval investigations?

The acronym NCIS stands for Naval Criminal Investigative Service, which is indeed a regulatory body associated with naval investigations. Established to conduct criminal investigations, protect naval personnel, and provide security for the Department of the Navy, NCIS plays a crucial role in ensuring law and order within naval operations. This agency is tasked with investigating a variety of crimes, ranging from espionage to fraud, and its responsibilities include collaborating with other law enforcement organizations to protect naval assets and personnel.

Understanding the function and scope of NCIS clarifies its significance in the context of naval investigations, making it the correct answer to this question. The other acronyms mentioned do not relate specifically to regulatory or investigative functions within the naval context.