A customer has the following non-virtualized servers： - three Exchange servers， each with 2.8 TB database  - five System i Domino servers， each with 2 TB database  - 20 TB usable capacitySun/SAP cluster  - 70 TB usable capacity of System p requirement  - annual growth rate of 12 TB usable capacity per year   What is the most cost-effective solution for three years（）

• A、IBM System Storage DS5020 with 300 GB drives
• B、IBM System Storage DS5300 with 300 GB drives
• C、IBM System Storage DS8700 with 300 GB drives
• D、IBM System Storage DS5020 with 1 TB SATA drives