Your company has an Active Directory domain. The main office has a DNS server named DNS1 that is  configured with Active Directory-integrated DNS. The branch office has a DNS server named DNS2 that  contains a secondary copy of the zone from DNS1. The two offices are connected with an unreliable WAN  link.   You add a new server to the main office. Five minutes after adding the server， a user from the branch  office reports that he is unable to connect to the new server.  You need to ensure that the user is able to connect to the new server.  What should you do（）

• A、Clear the cache on DNS2.
• B、Reload the zone on DNS1.
• C、Refresh the zone on DNS2.
• D、Export the zone from DNS1 and import the zone to DNS2.