Your network contains an Active Directory forest. The functional level of the forest is Windows Server 2008 R2.You plan to deploy DirectAccess.You need to configure the DNS servers on your network to support DirectAccess.What should you do？（）

• A、Modify the GlobalQueryBlockList registry key and restart the DNS Server service.
• B、Modify the EnableGlobalNamesSupport registry key and restart the DNS Server service.
• C、Create a trust anchor that uses a certificate issued by an internal certification authority (CA).
• D、Create a trust anchor that uses a certificate issued by a publicly trusted certification authority (CA).