Your company has a main office and one branch office. All servers run Windows Server 2003 Service Pack 2 (SP2). In the main office, a server named DNS1 hosts the primary DNS zone for contoso.com. You configure a primary zone for west.contoso.com on a DNS server named DNS2 in the branch office. All servers in the branch office are configured to have the west.contoso.com DNS suffix. You need to ensure that users in the main office can resolve server names in the branch office. The solution must meet the following requirements: Minimize the amount of DNS zone transfer traffic between the offices.Maintain the current name resolution process for users in the main office. 
What should you configure on DNS1?（）

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?（）