Examine the command： ALTER DATABASE ADD SUPPLEMENTAL LOG DATA （PRIMARY KEY） COLUMNS； What does the command accomplish？（）
- ACreates an additional copy of the database online redo log files.
- BStores the primary key column values of each row involved in a DML operation in the online redo log files.
- CStores the primary key column values of each row involved in a DML operation in the supplemental log files.
- DStores 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.