Your network consists of a single Active Directory domain. You have a domain controller named Server1 that runs Windows Server 2003 Service Pack 2 （SP2）.  The DNS service is installed on Server1. Server1 contains only Active Directory-integrated zones. Zone transfers are disabled for all zones. You need to back up the DNS zones on Server1.  What should you do？（）

• A、From a command prompt， run Nslookup.exe.
• B、From Windows Backup， back up the system state.
• C、From Windows Backup， back up %SystemRoot%/System32/DNS.
• D、From the DNS snap-in， right-click Server1 and then click Export List.