You have Exchange Server 2003 organization.
The organization contains a front-end server named FE1 and a back-end server named BE1. FE1 is accessible from the Internet by using mail.contoso.com. You plan to transition the organization to Exchange Server 2010.
You will deploy a Mailbox server named MBX1 and a Client Access server named CAS1. Users will access Outlook Web App (OWA) by using the URL https://mail.contoso.com. You need to recommend a DNS configuration for the external name of mail.contoso.com.
Which server should be associated with the name mail.contoso.com?()
A.BE1
B.CAS1
C.FE1
D.MBX1