You maintain an ASP.NET application by using the .NET Framework 3.5.

The application is currently accessed from desktop browsers. There are RadioButtonList objects on several pages in the application.

You are updating the application to meet the following requirements:

– When accessed from mobile devices, all RadioButtonList objects must be displayed as DropDownList objects to conserve screen space.
– When accessed from desktop browsers, the application must remain unchanged.

You need to ensure that the application meets the requirements.

What should you do?

A.
Create a class that extends the DropDownList class and replace all existing instances of the RadioButtonList class with it.

B.
Update the Page_PreRender event handler to dynamically create a DropDownList control when the Request.Browser.IsMobileDevice property is true.

C.
Create a class that extends the WebControlAdapter class and register it in a .browser file.

D.
Replace all existing instances of the RadioButtonList class with instances of the DropDownList class.