Which security measure could help address concerns about unauthorized physical access to a building?

The choice that best addresses concerns about unauthorized physical access to a building is the use of motion sensors. Motion sensors are designed to detect movement within a specified area, which makes them particularly effective in identifying unauthorized entries or movements in restricted locations. When integrated into a security system, motion sensors can trigger alarms or notifications when they sense any unexpected activity, providing a proactive approach to security.

This capability allows organizations to respond quickly to potential security breaches, enhancing overall safety. By monitoring areas like entrances and sensitive zones, motion sensors help ensure that only authorized personnel are allowed access, thereby mitigating the risks of unauthorized entry.

While other options, such as security cameras, can also provide valuable surveillance and evidence in case of an incident, they do not actively prevent unauthorized access in real-time. Access control lists are effective for managing who has permission to enter certain areas but require additional systems, such as keycards or biometric scanners, to enforce these rules. Fire alarms, while crucial for safety related to fires, do not address security concerning unauthorized physical access to the building.