单项选择题 A financial customer has three data centers that are approximately five kilometers apart. Their SAP application data needs to be kept synchronized within 10 milliseconds between the three sites. Which of the following solutions satisfies the customers recovery time objective?（）

单项选择题 A customer needs to achieve a very aggressive RTO of 30 minutes or less. A critical requirement is a continuous availability and disaster recovery solution for the mainframe environment. What IBM solution should be recommended to this customer?（）

单项选择题 A customer wants to expand their current storage environment, but has floor space for only two machine frames or two racks. Their environment consists of IBM SAN Volume Controllers and IBM DS4000 systems. The DS4000 systems are at end of lease. The customer wants the maximum number of disks possible in two frames. Which of the following solutions is best for this customer?（）