You create a control named ContosoUI for a Web application. You need to add the control to the toolbox of Microsoft Visual Studio .NET. Which two actions should you perform?（）

A、Create the ContosoUI control as a Web Control Library.

B、Create the ContosoUI control as a Web user control.

C、Within the Visual Studio .NET toolbox, browse to and select ContosoUI.ascx.

D、Within the Visual Studio .NET toolbox, browse to and select ContosoUI.dll.