Your Company has one main office and 50 branch offices. You have a wide area network (WAN) link
that connects all branch offices to the main office. The network consists of 10 Active Directory
domains. Users from all domains are located in the branch offices. You plan to configure each branch
office as an Active Directory site. The domain is configured as shown in the exhibit. (Click the Exhibit
button.)

You need to plan the deployment of domain controllers in the branch offices to meet the following
requirements:
Users must be able to log on if a WAN link fails.
Minimize replication traffic between offices.
What should you include in your plan?

A.
Implement a domain controller in each branch office. Enable Universal Group Membership
Caching.

B.
Implement a domain controller in each branch office. Configure DNS to use a single Active
Directory-integrated zone.

C.
Implement a domain controller in each branch office. Configure the domain controller as a global
catalog server.

D.
Implement a read-only domain controller (RODC) in each branch office. Configure the domain
controller as a global catalog server.

Explanation:
The replication traffic between the offices can be minimized with the use of Universal Group
Membership Caching, which is used to locally cache a user’s membership in universal groups on the
domain controller authenticating the user. This can help you to avoid global catalog (GC), which
causes the extra WAN traffic that the GC needs to replicate with other domain controllers in the
domain. The cached membership for UGMC can be refreshed every 8 hours to keep it up to date.
RODC cannot be configured in this scenario because it needs to use GC that increases the replication
traffic.
When to use and not use universal group membership caching
http://www.windowsnetworking.com/kbase/WindowsTips/Windows2003/AdminTips/ActiveDirecto
ry/Whentouseandnotuseuniversalgroupmembershipcaching.html