Your company has a single active directory domain. The company has a main office and three branch offices. The domain controller in the main office runs windows 2008 server and provides DNS for the main office and all of the branch offices.Each branch office runs windows server 2008. Users in the branch offices report that it takes a long time to access network resources. You confirm that there are no problems with WAN connectivity or bandwidth. You need to ensure that users in the branch offices are able to access network resources as quickly as possible. Which two actions should you perform? （）