Todd has been asked by the security officer to purchase a counter-based authentication system. Which of the
following best describes this type of system?

A.
A biometric system that bases authentication decisions on behavioral attributes.

B.
A biometric system that bases authentication decisions on physical attributes.

C.
An authentication system that creates one-time passwords that are encrypted with secret keys.

D.
An authentication system that uses passphrases that are converted into virtual passwords.