Your company has a main office and a branch office.   You discover that when you disable IPv4 on a computer in the branch office， the computer authenticates  by using a domain controller in the main office.   You need to ensure that IPv6-only computers authenticate to domain controllers in the same site.  What should you do（）

• A、Configure the NTDS Site Settings object.
• B、Create Active Directory subnet objects.
• C、Create Active Directory Domain Services connection objects.
• D、Install an Intra-Site Automatic Tunnel Addressing Protocol （ISATAP） router.