Your network contains two Exchange Server 2010 Edge Transport servers.  The network also contains five Hub Transport servers in two Active Directory sites. All e-mail sent to the network is received by the Edge Transport servers. You plan to configure anti-spam filtering.  You need to ensure that the anti-spam filtering configurations are applied to both Edge Transport servers. The solution must use a minimum amount of administrative effort.  What should you do？（）

• A、Configure EdgeSync synchronization.
• B、Implement Active Directory Federation Services （AD FS）.
• C、Join both Edge Transport servers to an Active Directory domain and then create a forest trust from the   internal forest.
• D、Manually configure settings on one Edge Transport server and then export the settings to the other Edge     Transport server.