You work as the enterprise exchange administrator at TestKing.com. TestKing.com makes use of Microsoft Exchange Server messaging solution. The TestKing.com network consists of a single ActiveDirectory domain named testking.com. A firewall at Testking.com separates the internal network and a perimeter network. The perimeter networkcontains an Exchange Server 2010 Edge Transport server. You have received instructions from the CIO to install an internal Exchange Server 2010 with the followingcriteria： 1. The support of EdgeSync synchronizaiton and encrypted delivery of outbound e-mail messages to theEdge Transport server. 2. The minimization of the attack surface of the internal network. What should you do？（）

• A、The best option is to use port 3309 and 25 from the internal network to the perimeter network.
• B、The best option is to use port 3309 and 636 from the internal network to the perimeter network.
• C、The best option is to use port 50636 and 25 from the internal network to the perimeter network.
• D、The best option is to use port 50636 and 135 from the internal network to the perimeter network.