Examine the CREATE DISKGROUP command used to create a disk group:  <br /> SQL> CREATE DISKGROUP misc EXTERNAL REDUNDANCY <br /> DISK ’ORCL: FRA3’ NAME misc1, ’ORCL: FRA4’ NAME misc2;  <br /> In which situation would you use this method of disk group creation?()
A、 When two-way disk mirroring is required for the allocation units
B、 When three-way disk mirroring is required for the allocation units
C、 When using hardware mirroring or RAID
D、 When disk mirroring is required for the Automatic Storage Management (ASM) disks