Two Factor Authentication (2FA)

• A. An extra layer of security after you enter your usual username and password
• B. A password manager
• C. Biometric only
• D. A single sign-on

Answer: (A)

Two-factor authentication adds a second piece of proof to verify who you are, after you’ve entered your usual username and password. The idea is that even if someone knows your password, they still need a second factor to gain access. That second factor can be a code from an authentication app, a text message, a hardware token, or a biometric check on your device. This extra step is what strengthens security by combining two different kinds of evidence.

The described option captures this exactly: it’s an extra layer of security that comes after you’ve entered your regular login credentials. The other choices describe related tools or concepts but aren’t two-factor authentication themselves: a password manager stores passwords; biometrics alone is a single factor; and a single sign-on is about signing in once for multiple services rather than adding a second verification step.