Which organization is designated as the CSO for the Department of Defense?

• A. Defense Security Service
• B. National Security Agency
• C. Office of the Director of National Intelligence
• D. Department of Homeland Security

Answer: (A)

The designated Chief Security Officer for the Department of Defense is the Defense Security Service because this organization serves as the central authority within DoD for implementing and overseeing security programs. It coordinates policies and oversight across all DoD components, handling key security functions such as personnel security investigations, facility clearances, and industrial security for contractors. That centralized role is what makes it the proper CSO, ensuring consistent security standards across the entire department.

Note that the Defense Security Service has evolved into the Defense Counterintelligence and Security Agency, but its mission remains to act as the DoD’s security umbrella, coordinating and enforcing the department’s security program. The other organizations mentioned—NSA, ODNI, and DHS—have distinct roles (intelligence, intelligence community coordination, and civilian/domestic security, respectively) and do not serve as the DoD’s CSO.