You are the messaging engineer for your company. The network is configured as shown in the following diagram.

You plan to deploy Exchange Server 2007.

You need to plan the placement of the Exchange Server 2007 servers to meet the following  requirements:

Member servers can only be installed on the internal network.

Outlook Web Access is accessible from the Internet.

Anti-spam filtering must be performed on the perimeter network.

Where should you place the Exchange Server 2007 servers?

A.
Place an Edge Transport server and a Client Access server on the perimeter network. Place a Hub Transport
server and a Mailbox server on the internal network.

B.
Place an Edge Transport server, a Client Access server, and a Hub Transport server on the perimeter
network. Place a Mailbox server on the internal network.

C.
Place an Edge Transport server on the perimeter network. Place a Client Access server, a Hub Transport
server, and a Mailbox server on the internal network.

D.
Place an Edge Transport server and a Hub Transport server on the perimeter network. Place a Client Access
server and a Mailbox server on the internal network.

Explanation:
Basic Exchange organization with multiple servers:

http://technet.microsoft.com/en-us/library/aa995940.aspx