Your network contains a single Active Directory forest. The forest contains two domains named contoso.com and sales.contoso.com. The domain controllers are configured as shown in the following  table.  
Server name  Domain  DNS zones hosted 
DC1  contoso.com  contoso.com  DC2  contoso.com  contoso.com  
DC3  sales.contoso.com  sales.contoso.com  DC4  
sales.contoso.com  sales.contoso.com  
All  domain  controllers  run Windows  Server  2008  R2.  All  zones  are  configured  as  Active  Directory-integrated zones.  
You need to ensure that contoso.com records are available on DC3.
Which command should you run（）