Your network contains a single Active Directory domain named contoso.com. The domain  contains two domain controllers named DC1 and DC2 that run Windows Server 2008 R2. DC1  hosts a primary zone for contoso.com. DC2 hosts a secondary zone for contosto.com. On DC1，  you change the zone to an Active Directory-integrated zone and configure the zone to accept  secure dynamic updates only.    
You need to ensure that DC2 can accept secure dynamic updates to the contoso.com zone.    
Which command should you run（）

Your network contains an Active Directory domain named contoso.com. You plan to deploy a  child domain named sales.contoso.com. The domain controllers in sales.contoso.com will be  DNS servers for sales.contoso.com.    
You need to ensure that users in contoso.com can connect to servers in sales.contoso.com by  using fully qualified domain names （FQDNs）.    
What should you do（）