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.