You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5. The application consumes an ASMX Web service.  The Web service is hosted at the following URL.  http：//www.contoso.com/TemperatureService/Convert.asmx  You need to ensure that the client computers can communicate with the service as part of the  configuration.  Which code fragment should you use？（）

• A、A
• B、B
• C、C
• D、D