A customer has requested that you provide the number of physical disks required to support its Microsoft Exchange 2007 Storage Groups. The company has 12,500 users each with an average workload of 1.2 IOPS. At peak activity, up to 10,000 users could be logged in to Exchange.
What other information is required to accurately calculate the number of required disk spindles to meet the user IOPS requirements?

A.
Public folders location and deleted item retention period

B.
Read/write ratio and write penalty

C.
Size of user mailbox, RAID type, and disk speed

D.
Size of user mailbox, read penalty, and RAID type