Your network contains a server named Server1 that has Microsoft SharePoint Foundation 2010
installed. You discover that users who access the SharePoint sites on Server1 by using a Windows
Phone device are redirected to the desktop version of the sites rather than the mobile version. You
need to ensure that the Windows Phone users are redirected automatically to the mobile version of
the sites. What should you modify from Server1?

A.
the site collection settings

B.
the Web.config file

C.
the site settings

D.
the Compat.browsers file

Explanation:
Modify the browser definition file (compat.browser)
The browser definition file contains a list of the mobile browsers and devices that can access mobile
views in SharePoint Server. When a user browses a SharePoint site from a mobile device, the mobile
browser submits to the site an HTTP GET request that includes a user agent string. If the mobile
browser and device model in the user agent string are listed in the browser definition file and the
isMobileDevice setting for the mobile browser is set to true, SharePoint Server redirects the mobile
browser to the mobile view of the site. Otherwise, a standard view of the site is shown in the mobile
browser. You can modify the file to change the redirect behavior of a mobile browser.
The browser definition file lists the mobile browsers and devices that are supported by SharePoint
Server. The file can be updated when product updates to SharePoint Server are released. You can
also modify the file to add a mobile browser or device to the list.
http://technet.microsoft.com/en-us/library/ff393836.aspx