Which of the following methods is commonly used to control building access?

The method commonly used to control building access is encapsulated by the option that includes all mentioned methods: proximity radio, cards, and biometric identification. Each of these methods plays a significant role in enhancing security and controlling who can enter a building.

Proximity radio systems work by using radio frequency identification (RFID) technology, allowing users to gain access to secured areas by simply being near a reader, usually equipped with a card or fob. This method is convenient and quick, requiring minimal effort from the user, while also allowing for tracking of access events.

Access cards are another prevalent solution; they can either be magnetic stripe cards or smart cards that carry embedded security features. These cards are typically issued to authorized individuals and can be deactivated if lost or if an individual no longer requires access, providing a flexible security measure.

Biometric identification takes security a step further by using unique physiological traits such as fingerprints, retina patterns, or facial recognition. This method significantly mitigates the risk of unauthorized access since biometric data cannot be easily copied or transferred.

Therefore, incorporating all of these methods—each with its own advantages—provides a comprehensive approach to building access control, making the collective option the most accurate choice.