A.to uniquely identify the archived log files with the restore operation
B.to uniquely identify the archived log files with the redo log group number
C.to uniquely identify the archived log files for each incarnation of the database
D.to uniquely identify the archived log files with the number of recovery operations performed

A.You must recover all data files to the required system change number （SCN）.
B.You must recover all data files， except those that are offline， to the required SCN .
C.You must recover all data files belonging to the USERS tablespace to the required SCN.
D.You cannot recover all data files because segment space management is performed manually for the undo tablespace.