Which statement best describes multi-factor authentication (MFA)?

Which statement best describes multi-factor authentication (MFA)?

• A. Using a password only
• B. Using a biometric factor only
• C. Using multiple factors, such as something you know and something you have
• D. Using two passwords

Answer: (C)

MFA means proving who you are using more than one type of evidence. The idea is to require factors from at least two different categories, so even if one factor is compromised, another is still needed to access the account. The best description here is using multiple factors from different categories, such as something you know (a password) and something you have (a code from an authenticator app or a hardware token). That combination captures the essence of MFA: authentication with more than one form of proof.

Using only a password is single-factor authentication. Relying on a biometric factor alone is also single-factor, since it uses just one category of evidence. Using two passwords, while requiring two secrets, still relies on the same category (something you know) and does not constitute multi-factor authentication.