When the Database Is Protected and the Virtual Snapshots Are

When the database is protected and the virtual snapshots are used from the end to verify LUN data consistency on the production end and the disaster recovery end. However, the disaster recovery end of the LUNd database can not be started normally. What is the possible reason? (Multiple choice.)

A) After a snapshot of the LUN of the redundancy site is created, the snapshot is not activated at the same time.
B) Disaster recovery storage side of the database resides in the cache has not been written to the hard disk.
C) When creating a snapshot on the disaster recovery end LUN, the production end is copying data to the disaster recovery end.
D) The production end and disaster recovery end adopt the disaster recovery solution of incremental LUN copy. The incremental data is abnormally interrupted during the synchronization process and has not been repaired.