Which setting should you change?

You have an Exchange Server 2010 organization.
Users access Outlook Web App by using the name mail.contoso.com.
You deploy Exchange Server 2013 to the existing organization.
You change the DNS record of mail.contoso.com to point to an Exchange Server 2013 Client Access
server.
The users report that they can no longer access their mailbox from Outlook Web App.
The OWA virtual directory in Exchange Server 2010 is configured as shown in the exhibit. (Click the
Exhibit button.)

You need to ensure that the users on Exchange Server 2010 can access Outlook Web App.
Which setting should you change?

A.
WindowsAuthentication

B.
FormsAuthentication

C.
LegacyRedirectType

D.
FailbackUri