During an online database backup, which files must be saved to ensure that the Oracle database can be restored to an internally consistent state? Please choose the correct answer.
A . The tablespace data files, the database control file, and the database parameter file
B . Oracle online redo log files and the database control file
C . The Oracle executables, the database parameter file, and the tablespace data files
D . Tablespace data files, the database control file and all database redo logs written during the online backup
Answer: B