Your network contains a DNS server named Server1 that runs Windows Server 2008 R2.Root hints for Server1 are configured as shown in the exhibit. (Click the Exhibit button.)You need to add root hints to Server1.What should you do first？（）

• A、Disable recursion.
• B、Delete the . (root) zone.
• C、Restart the DNS Server service.
• D、Remove all conditional forwarders.