How can you reverse the effects of an ALTER DISKGROUP ... DROP DISK command if it has not yet completed？（）  

• A、 Issue the ALTER DISKGROUP ... ADD DISK command.
• B、 Issue the ALTER DISKGROUP ... UNDROP DISKS command.
• C、 Issue the ALTER DISKGROUP ... DROP DISK CANCEL command.
• D、 Retrieve the disk from the Recycle Bin after the operation completes.