An authentication method uses smart cards as well as usernames and passwords for authentication. Which of the following authentication methods is being referred to?

Anonymous authentication involves no credentials and provides no verification of user identity.

Mutual authentication is when both the client and server authenticate each other, but it does not specify the number of factors used for authentication.

Multi-factor authentication (MFA) requires a user to provide two or more distinct verification factors from different categories, such as 'something you know' (password) and 'something you have' (smart card). This combination significantly increases security by making it much harder for unauthorized individuals to gain access even if one factor is compromised.

Biometrics refers to using unique physical or behavioral characteristics (something you are) for authentication, which is a type of factor, not a method that combines multiple distinct factors like smart cards and passwords.