Explanation: Biometrics is a method of authentication that uses physical characteristics, such as fingerprints, scars, retinal patterns, and other forms of biophysical qualities to identify a user. Nowadays, the usage of biometric devices such as hand scanners and retinal scanners is becoming more common in the business environment. It is the most secure method of authentication. Answer: B is incorrect. Username and password is the least secure method of authentication in comparison of smart card and biometrics authentication. Username and password can be intercepted. Answer: D is incorrect. Smart card authentication is not as reliable as biometrics authentication. Answer: C is incorrect. Anonymous authentication does not provide security as a user can log on to the system anonymously and he is not prompted for credentials.