In user-managed backup and recover procedures， how are data files backed up？ （）

A.Only when the new master site already has existing replication groups. 
B.By issuing a single command to create, populate, and activate the new master. 
C.When the master definition site is not the same for all of the master groups. 
D.Without impacting end users who are executing data manipulation language (DML) commands on the replicated tables.

A.Automatically versions all tables.
B.Automatically installed with Oracle9i.
C.Merges changes with parent rows or discard changes.
D.Provides mechanism to identify and resolve conflicts.
E.Allows for version enabling tables by use of a packages procedure.