You run the following commands：   RMAN> list expired backup； RMAN> delete expired backup；   What will happen to the backup set pieces associated with the backups that appear in the list expired backup command？（）  

• A、 They will be renamed.
• B、 Nothing will happen to them. The backup set pieces do not exist.
• C、 They will be deleted immediately since they are not in the flash recovery area.
• D、 You will need to manually remove the physical files listed in the output of the commands.
• E、 They will become hidden files and removed 10 days later.