A system requires users to log in with a username, a password, and a smart card. This authentication approach is best described as:

• A. Single-factor authentication
• B. Multi-factor authentication
• C. Biometric-only authentication
• D. Passwordless authentication

Answer: (B)

This approach uses more than one credential from different categories, which is multi-factor authentication. Here, the user provides a password (something you know) and a smart card (something you have).Both are separate factors, so combining them verifies identity using multiple factors. The username is just an identifier and isn’t a separate authentication factor, so it doesn’t count as an additional factor. This isn’t single-factor authentication, since more than one factor is required; it isn’t biometric-only or passwordless, since a password and a smart card are present.