You issue the following RMAN command to set a retention policy on a database：   RMAN>CONFIGURE RETENTION POLICY TO REDUNDANCY 2；   What will be the outcome of issuing this command？（）  

• A、 After two days，a backup will be marked obsolete
• B、 After two days，a backup will be deleted from the media
• C、 If the RMAN repository has records of two or more recent backups of a file，then older backups will be deleted from the media.
• D、 If the RMAN repository has records of two or more recent backups of a file then older backups will be marked obsolete.