What is the impact of the results of the output of the following command？（）   RMAN> report unrecoverable database；  Report of files that need backup due to unrecoverable operations  File Type of Backup Required Name  4 full or incremental C:///ORACLE/ORADATA/ORCL/USERS01.DBF  

• A、 There are no backup sets with any backups of the users01.dbf datafile.
• B、 The users01.dbf datafile has had unrecoverable operations occur in it. It will need to be backed up or some data loss is possible during a recovery.
• C、 The users01.dbf datafile is corrupted.
• D、 The users01.dbf datafile backup exceeds the retention criteria.
• E、 The last backup of the users01.dbf datafile failed and must be rerun.