Your network contains a single Active Directory domain.  You have an Exchange Server 2010 organization that contains a Hub Transport server named Hub1. Hub1 receives all e-mail messages that are sent to your organization from the Internet.  A new company security policy states that domain-joined servers must not be accessible directly from theInternet.  You need to create a message hygiene solution to meet the following requirements： .Comply with the new security policy .Minimize the amount of spam that is delivered to the internal Exchange servers in the organization What should you do first？（）

• A、Deploy an Edge Transport server， and then configure EdgeSync synchronization.
• B、Deploy a new Hub Transport server， and then install the anti-spam transport agents.
• C、Deploy a new Hub Transport server， and then deploy Active Directory Federation Services （AD FS）.
• D、Deploy an Edge Transport server， and then disable Active Directory Lightweight Directory Services（AD     LDS）.