Your network contains an Active Directory domain. The domain contains two domain controllers  named DC1 and DC2.   DC1 hosts a standard primary DNS zone for the domain. Dynamic updates are enabled on the zone. DC2  hosts a standard secondary DNS zone for the domain.   You need to configure DNS to allow only secure dynamic updates.  What should you do first（）

• A、On DC1 and DC2， configure a trust anchor.
• B、On DC1 and DC2， configure a connection security rule.
• C、On DC1， configure the zone transfer settings.
• D、On DC1， configure the zone to be stored in Active Directory.