You have lost all your SYSTEM tablespace datafiles （system_01.dbf and system_02.dbf） nd the database has crashed.  What would be the appropriate order of operations to correct the situation？（）   a. Mount the database with the startup mount command.  b. Take the SYSTEM datafile offline with the alter database command.  c. Restore the SYSTEM_01.dbf datafile from backup media with the required archived redo logs.  d. Restore all SYSTEM tablespace-related datafiles from backup media. e. Issue the recover tablespace SYSTEM command.  f. Issue the recover datafile SYSTEM_01.dbf command.  g. Open the database with the alter database open command.  h. Open the database with the alter database open resetlogs command.

• A、a， c， f， g
• B、b， d， e， h
• C、a， b， c， f， g
• D、d， a， e， g
• E、b， c， f， e， g