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.
Create Active Directory Domain Services connection objects.
D. Install an Intra-Site Automatic Tunnel Addressing Protocol （ISATAP） router.