You have configured the flash recovery area to store online redo log files， control files， archived redo logs and RMAN backups. Which of the following files can you successfully delete from the flash recovery area if you want to reclaim the space within it？（）
A: multiplexed control files
B: RMAN obsolete backups
C: multiplexed online redo log files
D: archived redo logs that have not been copied to tape
出自：Oracle认证