问题：

[单选]

You work as a Web Developer at Certkiller.com. You are in the process of creating a mobile Webapplication. You use Microsoft ASP.NET 3.5 to create the Web application. 
In an assembly named MobileUser the following code exists： 
namespace Certkiller.MobileUser { 
public class Capabilities { 
public static bool IsEnhancedDevice（MobileCapabilities capabilities， string optional） { 
return （capabilities["AJAX"] == Boolean.TrueString && 
capabilities["Silverlight"] == Boolean.TrueString）； 
} 
} 
} 
The following code is contained on a page in the Web application： 
MobileCapabilities capabilities = （MobileCapabilities）Request.Browser； 
bool isEnhancedDevice = capabilities.HasCapability（"SilverlightAndAjax"， null） 
You have to make sure that the code calls the IsEnhancedDevice method of the Capabilities class.You configure the Web.config file to accomplish this.
What should you do？（）

A . A
B . B
C . C
D . D