Which of the following is an example of multifactor authentication?

Multifactor authentication (MFA) is a method of verifying a user’s identity by requiring more than one factor, such as something the user knows, something the user has, or something the user is1. A short message service (SMS) message sent to a phone and an access PIN is an example of MFA, as it combines two factors: something the user has (the phone) and something the user knows (the PIN). This makes the authentication process more secure than using only a password, which is a single factor. Other examples of MFA include using a biometric scan (such as a fingerprint or a face recognition) and a password, or using a hardware token (such as a smart card or a USB key) and a password1. References: 1: CompTIA Cloud Essentials+ Certification Study Guide, Second Edition (Exam CLO-002), Chapter 3: Cloud Planning, Section 3.2: Cloud Adoption, Subsection 3.2.1: Identity and Access Management