What mechanism can prevent unauthorized access by using biological traits?

The correct answer is based on the principle that biometric systems utilize unique biological traits of individuals to verify their identity, making them a powerful mechanism for preventing unauthorized access. These traits can include fingerprints, facial recognition, iris patterns, or voice patterns, each of which is distinctly personal to an individual.

By relying on the uniqueness and variability of these biological traits, biometric systems create a robust form of security that is difficult to replicate or forge, thereby ensuring that only authorized users can gain access to secured areas or systems. This technology enhances security by adding an additional layer of authentication that traditional passwords or keys do not provide.

The other options involve different security measures: audit trails track user activities, access control lists define permissions for users regarding resource access, and locking mechanisms physically secure spaces. However, none of these methods utilize unique biological attributes to authenticate individuals, which is the defining feature of biometric systems.