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.