Your company’s network includes 150 client computers that run Windows Vista Business. The company does not participate in the Microsoft Software Assurance program. You plan to implement a virtual desktop infrastructure （VDI） that includes 150 VDI sessions. You acquire three new servers that have four quad-core CPUs each. You need to choose the appropriate licenses. Which licensing solution should you choose？（）

• A、150 Windows Virtual Enterprise Centralized Desktop （VECD） licenses
• B、150 Windows Vista Business licenses
• C、3 Windows Server 2008 R2 Datacenter licenses
• D、150 Windows 7 Professional Upgrade licenses and Software Assurance