There is the possibility that hdisk1 in the root volume group is going bad. A decision has been made to replace the disk. After saving all of the data from the disk and unmounting any filesystems on the disk, which of the following commands should be run before removing the disk from the system?（）

• A、chgv -a n hdisk rootvg; rmdev -1 hdisk1 -d
• B、rmdev -1 hdisk1 -d; reducevg -df rootvg hdisk1
• C、reducevg -df rootvg hdisk1; rmdev -1 hdisk1 -d
• D、reducevg -df rootvg hdisk1; rmdev -1 hdisk1