What security functions must be performed for a physical security system to protect DoD assets?

The correct answer encompasses the complete range of security functions necessary for a robust physical security system to effectively protect Department of Defense (DoD) assets. This includes not just routine updates of technology, monthly drills, and nighttime surveillance, but also other critical elements that ensure comprehensive risk mitigation.

A physical security system is designed to deter, detect, respond to, and recover from security threats, which requires a multifaceted approach. Regular updates of technology are crucial as they help integrate the latest tools and systems that enhance security measures. Monthly drills ensure that personnel are adequately trained and familiar with procedures, promoting readiness and a swift response during actual incidents. Nighttime surveillance, alongside other forms of monitoring, plays a vital role in detecting any unauthorized access or suspicious activities during hours when visibility and access control challenges may increase.

By selecting all of the above as the correct answer, it acknowledges the importance of a coordinated security strategy that utilizes various security functions to address the complexities of safeguarding DoD assets effectively. A singular focus on just one aspect, as seen in the other choices, would not provide the holistic protection needed in today's security landscape.