Which set of action satisfy the requirement for multi-factor authentication?
A.The user swipes a key fob, then clicks through an email link. B.The user enters a user name and password, and then clicks a notification in an authentication app on a mobile device. C.The user enters a PIN into an RSA token, and then enters the displayed RSA key on a login screen. D.The user enters a user name and password and then re-enters the credentials on a second screen.正确答案B
