A. A list of files that require a backup within 3 days
B. A list of files requiring more than 3 days of archivelogs to apply
C. A list of files that RMAN recommends be backed up only once in every three days，based on low volatility
D. A list of files for which a backup as already been performed in the last three days and which is  required to be backed up again based on the high number of transactions performed on them

A. If the lost redo log group is ACTIVE, you should first attempt to clear the log file.
B. If the lost redo log group is CURRENT, you must clear the log file.
C. If the lost redo log group is ACTIVE, you must restore, perform cancel-based incomplete recovery, and open the database using the RESETLOGS option.
D. If the lost redo log group is CURRENT, you must restore, perform cancel-based incomplete recovery, and open the database using the RESETLOGS option.