Your network consists of an Active Directory forest named contoso.com. All servers run Windows Server 2008 R2. All domain controllers are configured as DNS servers. The contoso.com DNS zone is stored in the ForestDnsZones Active Directory application partition. You have a member server that contains a standard primary DNS zone for dev.contoso.com. You need to ensure that all domain controllers can resolve names for dev.contoso.com. What should you do（）
- ACreate a NS record in the contoso.com zone.
- BCreate a delegation in the contoso.com zone.
- CCreate a standard secondary zone on a Global Catalog server.
- DModify the properties of the SOA record in the contoso.com zone.