There is a power outage and all servers are shut down properly by the uninterruptible power supply（UPS） software. When one of the servers starts up it displays a logical drive failed error. This server has two processors，16GB of memory， and a RAID 5 array with 10 drives.  Which of the following is the MOST likely cause？（）

• A、 A failed RAID controller
• B、 Two failed processors
• C、 Two failed sticks of memory
• D、 Two failed drives