Which two statements are true about Block Media Recovery （BMR）？（）
- A BMR increases the Mean Time To Recover （MTTR）.
- B BMR can only be implemented using Recovery Manager （RMAN）.
- C The blocks that need to be recovered are accessible during BMR.
- D BMR cannot be performed using cumulative incremental backups.
- E The datafile must be restored if most of the blocks in the datafile are corrupt.