Your virtual environment includes Microsoft Virtual Server 2005 R2 and third-party hypervisors. The virtual machines （VMs） include messaging， application， and database servers. You intend to standardize on Windows Server 2008 R2 Hyper-V servers.  You are developing a migration plan by using the Microsoft Assessment and Planning （MAP） Toolkit. You need to gather the necessary information to analyze the current virtual environment.  Which MAP assessment should you choose？（）

• A、Application Virtualization Assessment
• B、Virtual Machine Inventory
• C、Windows Server 2008 R2 Readiness
• D、Windows Server Role Discovery