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?

A.
Create a DNS forwarder.

B.
Create a DNS delegation.

C.
Configure root hint servers.

D.
Configure an alternate DNS server on all client computers.