What is the term for authentication requiring users to verify multiple factors?

• A. Multi-factor Authentication
• B. Single Sign-On
• C. OAuth 2.0
• D. Kerberos

Answer: (A)

The concept being tested is strengthening authentication by requiring more than one verification factor. When you verify identity using multiple factors, you’re using different types of evidence to prove who someone is—typically something you know (like a password), something you have (like a code from an authenticator or a hardware token), or something you are (a biometric trait). Requiring two or more of these factors makes it much harder for an attacker to gain access because compromising one factor isn’t enough.

This is why the term for this approach is multi-factor authentication. The other options don’t fit the needed idea: single sign-on is about using one login to access multiple systems, OAuth 2.0 is an authorization framework rather than an authentication factor concept, and Kerberos is a specific authentication protocol using tickets rather than a multi-factor requirement.