Define "access control" as it relates to airport security.

Access control in the context of airport security is fundamentally concerned with ensuring that only authorized personnel can enter secure areas of the airport. This involves the implementation of various mechanisms and policies designed to restrict access effectively. These could include identification signage, security badges, biometric systems, or electronic locks and surveillance systems that are in place to monitor and manage who can enter these sensitive areas.

By controlling access, airports can significantly reduce the risk of unauthorized activities that could compromise safety and security. This is especially critical in areas such as runways, baggage handling, and check-in zones, where the presence of unauthorized individuals could lead to serious security breaches or incidents.

In contrast, other options relate to different aspects of airport security, such as employee training, controlling public area restrictions, and the passenger screening process—none of which directly address the mechanisms for restricting access to secure areas specifically.