A.Flashback logs are automatically purged when db_flashback_retention_target is set lower than the time they have already been retained.

B.Flashback logs are automatically purged whenever the value
Of DB_FLASHBACK_RETENTION_TARGET is changed.

C.Flashback logs are monitored and proactively deleted when beyond the retention period defined in db_flashback_retention_target before there is space pressure.

D.Flashback logs are monitored for being older than the retention period defined in db_flashback_retention_target and can be deleted by an administrator written event trigger.

E.Flashback logs are monitored and proactively deleted when beyond the retention period defined in DB_flashback_retention_TARGET only after there is space pressure