Which of the following is an example of a physical security control?

Physical security controls are measures that protect physical assets, including buildings, equipment, and personnel, from unauthorized access or harm. Examples of physical security controls include the use of security guards to monitor and manage access to facilities and surveillance cameras that help to deter crime and monitor activities in and around a location.

In the context of this question, the inclusion of security guards and surveillance cameras represents direct physical measures that safeguard premises and individuals. They help in detecting, deterring, and responding to security incidents in real-time.

On the other hand, security protocols, data encryption, and network firewalls are typically associated with information security or cybersecurity measures, which focus on protecting data and networks rather than physical assets. They do not involve the physical security of a facility or its occupants directly.