An administrator is ordering a new Power 550. They will mirror rootvg and are concerned about single points of failure. Which of the following features should be ordered？（）

• A、Dual I/O planar， dual disk drives， dual SCSI adapters
• B、Dual disk drive enclosures， dual disk drives， extra media bay
• C、Dual disk drive enclosures， dual disk drives and dual SCSI adapters
• D、Dual I/O planar， extra media bay， dual disk drives