What biometric method could be used to identify a user?

Biometric methods for user identification rely on unique physical characteristics to authenticate individuals. A fingerprint scan is a prime example of such a method, as it scans the distinct patterns of ridges and valleys on a person's fingertip. This method is advantageous for security because fingerprints are unique to each individual and are difficult to replicate, making them a reliable way to confirm a user’s identity.

In contrast, the other choices do not focus on identifying a user through biometric means. A password strength meter helps users create stronger passwords but does not employ any physical attributes for identification. Firewall settings and antivirus software are security tools that protect systems from unauthorized access and malware but are not used for user identification in the biometric sense. Thus, the fingerprint scan stands out as the accurate option for biometric identification.