A.Creates an additional copy of the database online redo log files. 
B.Stores the primary key column values of each row involved in a DML operation in the online redo log files. 
C.Stores the primary key column values of each row involved in a DML operation in the supplemental log files. 
D.Stores the old and new primary key column values of each row involved in a DML operation only when the primary key is modified in the online redo log files.