Which authentication method requires a user to present a physical characteristic?

Biometric authentication uses unique physical characteristics, such as fingerprints, facial recognition, or iris scans, to verify a user's identity. This method directly fulfills the requirement of presenting a physical characteristic. Password authentication relies on something a user knows, not a physical characteristic. Multifactor authentication combines two or more independent credentials from different categories (e.g., something you know, something you have, something you are), but the term itself doesn't specify the "physical characteristic" aspect; it's a broader concept that can include biometrics. Certificate authentication uses digital certificates to verify identity, which is something a user has or is presented to them, not a physical characteristic of the user.