You have an Exchange Server 2010 organization. You plan to deploy a database availability group （DAG）. You need to recommend disk configurations for the servers in the organization. The solution must minimize costs. What should you recommend？（）
- A7200 RPM SATA hard disks in a Direct Attach Storage （DAS）
- B7200 RPM SATA hard disks in a Network Attached Storage （NAS）
- C15000 RPM SAS hard disks in a Network Attached Storage （NAS）
- D15000 RPM SAS hard disks in a Fibre Channel （FC） Storage Area Network （SAN）