Which Set of Actions Satisfy the Requirement for Multifactor Authentication

Which set of actions satisfy the requirement for multifactor authentication?

A) The user enters a user name and password, and then re-enters the credentials on a second screen.
B) The user swipes a key fob, then clicks through an email link.
C) The users enters a user name and password, and then clicks a notification in an authentication app on a mobile device.
D) The user enters a PIN into an RSA token, and then enters the displayed RSA key on a login screen.