A technician is implementing multifactor authentication for logins to the network. The network already requires a username and password to authenticate users. Which of the following should the…

A passphrase is a variation of a password and falls under the 'something you know' category, the same factor type as the existing password, so it does not introduce a new authentication factor.

Knowledge-based authentication relies on security questions, which are also classified as 'something you know' and therefore do not add a distinct factor beyond the existing username and password.

In MFA implementations such as Windows Hello for Business, a PIN is device-bound - it is registered to and only valid on a specific enrolled machine - making it functionally a 'something you have' factor rather than a simple reusable secret. Adding this device-bound PIN alongside the existing username and password creates a two-factor authentication setup that meets the MFA requirement without requiring additional biometric hardware infrastructure.

A thumbprint is a biometric 'something you are' factor that is valid for MFA but typically requires dedicated fingerprint reader hardware at each network login point, making it less practical than a device-bound PIN for this network authentication scenario.