You are the messaging engineer for your company. The company has 10,000 users worldwide. All users connect to their mailboxes by using Outlook Web Access. The company is transitioning from Microsoft Exchange Server 2003 to Exchange Server 2007. You plan to deploy five Client Access servers. You need to provide recommendations to improve the performance of Outlook Web Access. What should you do?

A.
On all Client Access servers, edit the TMP variable and specify a dedicated physical disk.

B.
On all Exchange Server 2003 servers, edit the TMP variable and specify a dedicated physical disk.

C.
Install an Edge Transport server on a new server.

D.
Install a Hub Transport server on a new server.

Explanation:
For all Exchange 2007 protocols, content conversion takes place on the CAS. WebDAV content conversion, for legacy OWA clients, occurs on the 2003 Mailbox server. When a client requests data that must be converted on a CAS, this data is accessed from the 2003 Mailbox server, converted in the Mailbox server TMP folder, and sent to the CAS. To improve performance, the TMP folder shouldnt be on the same LUN as the page file and operating system.

http://technet.microsoft.com/en-us/library/bb738154.aspx