You performed the RMAN database backup with the KEEP option. Which two statements are true regarding this backup？（）

• A、 The backup contains data files， the server parameter file，and the control file even if the control file  autobackup is disabled.
• B、 The KEEP option overrides the configured retention policy.
• C、 The backup contains only data files and archived redo log files.
• D、 The KEEP option is an attribute of an individual backup piece.