The 'Something you are' factor refers to biometric authentication methods, such as fingerprints, facial recognition, or retina scans. Among the given options, only 'FIDO2' aligns with biometric authentication as it supports methods that include biometrics. Options like email, phone call, and security questions do not satisfy the 'Something you are' requirement. The CyberArk Identity mobile app mentioned does not specify biometric use, so it cannot be confirmed as fulfilling 'Something you are' without further information.