Your network contains two Active Directory sites named Site1 and Site2. Only Site1 can be accessed from the Internet. You have an Exchange Server 2010 organization.  You deploy a Client Access server in Site1 and enable Windows Integrated Authentication for OutlookWeb App （OWA）.  In Site2， you deploy a Mailbox server and a Client Access server.  You need to configure the Exchange organization to meet the following requirements：.Allow users to access their mailboxes from the Internet by using OWA  .Prevent authentication prompts from displaying when users connect to OWA by using domain- joinedcomputers that are connected to the internal network  What should you do？（）

• A、Modify the Exchange virtual directory on the Client Access server in Site1.
• B、Modify the Exchange virtual directory on the Client Access server in Site2.
• C、Modify the OWA virtual directory on the Client Access server in Site1.
• D、Modify the OWA virtual directory on the Client Access server in Site2.