Which procedure would you use to minimize the effect of the I/Os of this reorganization on ongoing database operations?

You want to reorganize the DATA diskgroup while continuing database operations. The DATA
diskgroup was created using normal redundancy having one disk per failure group. The two disks
used are /dev/sdal and /dev/sda2.
You plan to drop the existing disks and add the /dev/sdb1 and /dev/sdb2 disks to failure group
FG_C and the /dev/sdcl and /dev/sdc2 disks to failure group FG_D.
Which procedure would you use to minimize the effect of the I/Os of this reorganization on
ongoing database operations?

A.
Set rebalance power to 0 for diskgroup DATA.
Add failure group FG_C with all the /dev/sdb disks.
Add failure group FG_D with all the /dev/sdc disks.
Drop disks/dev/sda1 and /dev/sda2.
Set rebalance power to 1 for diskgroup DATA.

B.
Set rebalance power to 0 for diskgroup DATA.
Add failure group FG_C with all the /dev/sdb disks.
Add failure group FG_D with all the /dev/sdb disks.
Drop disks/dev/sda1 and /dev/sda2.
Set rebalance power to 9 for diskgroup DATA.

C.
Set rebalance power to 9 for diskgroup DATA.
Add failure group FG_C with all the /dev/sdb disks.
Add failure group FG_D with all the /dev/sdc disks.
Drop disks /dev/sda1 and /dev/sda2.
Set rebalance power to 0 for diskgroup DATA.

D.
Set rebalance power to 0 for diskgroup DATA
Drop disks /dev/sdal and /dev/sdb disks.
Add failure group FG_C with all the /dev/sdb disks.
Add failure group FG_D with all the /dev/sdc disks
Set rebalance power to 1 for diskgroup DATA.

Explanation:
Oracle Automatic Storage Management