Which of the following describes the error of the three-level rollback function supported by iMaster NCE-Fabric?

Which of the following describes the error of the three-level rollback function supported by iMaster NCE-Fabric?
A . Network-wide rollback allows you to roll back the entire network configuration to before the configuration change to quickly restore services
B . The three-level rollback function supports manual backup and automatic backup, and supports automatic recovery when the network is abnormal
C . Tenant snapshots are backups and restores of the network at tenant granularity
D . Service rollback supports single-point service recovery

Answer: B