A company needs to increase the security controls on its servers. An administrator is implementing MFA on all servers using cost effective techniques. Which of the following should the administrator use to satisfy the MFA requirement?
正解:B
Push notifications are messages that are sent from an application or a service to a user's device without requiring the user to open or request them. They can be used as a cost-effective technique for implementing MFA (Multi-Factor Authentication) on servers by sending verification codes or approval requests to the user's smartphone or tablet when they try to log in to the server. Verified References: [Push notifications], [MFA]