Which of the following is used to describe an authentication scenario in which a user logs in using a pin and a security token

Two-factor authentication (A form of multi-factor authentication)

Explanation:

Though the question didn't put in the options, there are no two ways about the answer than the following:

When there is a case of using two or more authentication methods to authenticate a user into a system, the scenario is called a multi-factor authentication. In the case where the authentication methods are specifically and expressly given to be two (PIN and security token in this case), it is known as 2-factor or two-factor authentication.

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Two-factor authentication.

Explanation:

Multi-factor authentication is a security technique used to verify and authenticate users to an account, using more than one factor related to the user. It has to do with multiple factors like what the user knows, what the user have and who the user is. The respective example of these factors are using password or pin, security token and bio-metrics to access an account.

A two-factor authentication is a type of multi-factor authentication that uses two factors to authenticate a user, it could be using a PIN or password and a security token or bio-metrics.