A user attempting to log on to a workstation for the first time is prompted for the following
information before being granted access: username, password, and a four-digit security pin that
was mailed to him during account registration. This is an example of which of the following?

A.
Dual-factor authentication

B.
Multifactor authentication

C.
Single factor authentication

D.
Biometric authentication

Explanation:
Multi-factor authentication (MFA) is a method of computer access control which a user can pass
by successfully presenting authentication factors from at least two of the three categories:
knowledge factors (“things only the user knows”), such as passwords
possession factors (“things only the user has”), such as ATM cards
inherence factors (“things only the user is”), such as biometrics
In this question a username, password, and a four-digit security pin knowledge are all knowledge
factors (something the user knows). Therefore, this is single-factor authentication.