Your database is functioning in NOARCHIVELOG mode. Your database contains 15 tablespaces. You want to use Recovery Manager （RMAN） to perform backups.  Which two backups would you be able to perform when the database is being accessed by users？（）

• A、backup of offline tablespaces
• B、backup of read­only tablespaces
• C、backup of system­critical tablespaces
• D、backup of online， locally managed tablespaces
• E、backup of read/write dictionary­managed tablespaces