A system administrator notices that one of the mirrored disks, hdisk7 on datavg, has had a hardware failure. What is the best method of recover without causing additional problems?（）

A. unmirrorvg datavg hdisk7 reducevg datavg hdisk7 replace the physical volume, run cfgmgr extendvg datavg hdisk7 mirrovg datavg hdisk7
B. varyoffvg datavg Rmdev -l hdisk7 -d Replace the physical volu,e run cfgmgr The system will automatically remirror when the disk is replaced
C. unmirrorvg datavg hdisk7 rmdev -l hdisk7 - d replace the physical volume, run cfgmgr extendvg datavg hdisk7 The system will automatically remirror when the disk is replaced.
D. unmirrorvg datavg hdisk7 reducevg data hdisk7 rmdev -l hdisk7 -d replace the physical volume, run cfgmgr extendvg datavg hdisk7 mirrovg datavg