Which of the following refers to biological characteristics used for identification?

The correct answer is biometrics because it encompasses the biological characteristics that are unique to individuals and can be used for identification purposes. Biometric systems analyze measurable physical traits such as fingerprints, facial recognition, iris patterns, or voice recognition. These characteristics are highly specific to each person, making biometrics a reliable method for authenticating identity.

In different contexts, credentials typically refer to the information or documentation that verifies someone's qualifications or identity, which may not necessarily be biological. Authorization is a security measure that involves determining what permissions an authenticated user has after their identity has been verified. An identification card represents a physical form of identification containing various personal details but does not inherently involve biological characteristics. Thus, while the other options relate to aspects of identity or access control, it is biometrics that directly pertains to the specific biological traits used in identification processes.