You want to configure the Flashback Database feature and retain flashback logs for three days. 
Presently the database is open and configured in ARCHIVELOG mode. The following steps must be performed in the correct sequence to do this：  
1. Set the retention target： 
SQL> ALTER SYSTEM SET DB_FLASHBACK_RETENTION_TARGET=4320； 
2. Enable Flashback Database： 
SQL> ALTER DATABASE FLASHBACK ON； 
3. Mount the database： 
SQL> STARTUP MOUNT EXCLUSIVE 
4. Shutdown the instance： SQL> SHUTDOWN IMMEDIATE 
5. Open the database： 
SQL> ALTER DATABASE OPEN；  
Choose the correct sequence.（）

A. ALTER DISKGROUP misc MOUNT
B. ALTER DISKGROUP misc DROP DISK misc2
C. ALTER DISKGROUP misc CHECK ALL NOREPAIR
D. ALTER DISKGROUP misc RESIZE ALL SIZE 1023m
E. ALTER DISKGROUP dgroupA ADD DISK ’/devices/A*’

A. You can use RMAN stored scripts
B. Recovery is faster if data is stored in catalog in addition to the control file
C. You can store backup information of all registered databases in one place
D. Database backups are automatically deleted when they are older than the specified time period

A. Allow the database to continue running，drop the TEMP tablespace，and then re-create it with new tempfiles
B. Shut down the database， restore and recover the tempfile from backup，and then open the database with RESETLOGS
C. Allow the database to continue running，take the TEMP tablespace offline，drop the missing tempfile，and then create a new tempfile
D. Allow the database to continue running，add a new tempfile to TEMP tablespace with a new name，and drop the tempfile that has been corrupted