Which type of access control system involves physical keys?

The correct answer pertains to a mechanical key access control system, which utilizes physical keys for securing and permitting access to physical spaces. In this system, a lock is designed to correspond with a specific key, allowing only individuals possessing that key to open the lock and gain entry. This straightforward and traditional method of physical security has been employed for centuries and relies entirely on the presence of the key, making it a tangible and easily understandable form of access control.

When examining the other choices, a biometric access system employs unique biological traits, such as fingerprints or retinal patterns, to grant access, thus eliminating the need for physical keys. An electronic card access system relies on cards equipped with electronic chips or magnetic strips, which must be swiped or scanned to unlock doors, also removing the necessity for conventional keys. Remote access control typically relates to digital systems that can be managed via a computer or mobile device to monitor and control access, further highlighting the absence of physical key components.