Which of the following combines something you know (e. g. password) with something you are (e. g. fingerprint) or something you possess (e. g. USB stick) and can also employ a certificate system that adds a distinct third layer to the authentication process?

Two-factor authentication

Explanation: Two-factor authentication is a type of multi-factor authentication which provides an additional layer or extra protection to a system's information, it ensures that a system user is only granted access upon successful provision of two different pieces of evidence to an authentication machine. The extra layer of information which could be a fingerprint or USB stick in addition to a password protection is employed in other to mitigate the risk of malicious attack or unauthorized access to information systems.