Your company has a single Active Directory forest that has six domains. All DNS servers in the forest run Windows Server 2008. You need to ensure that all public DNS quieries are channeled through a singlecahing- only DNS server. Which two actions should you perform？（） 

• A、Disable the root hints
• B、Enable BIND secondaries
• C、Configure a forwarder to the caching DNS server
• D、Configure a GlobalNames host （A） record for the hostname of the caching DNS server