You are an enterprise application developer. You create a Microsoft Windows client application that consumes a third-party Web service. The Web service is secure and requires user credentials to be passed through SOAP headers. The Web service is currently in its beta. The URL of the Web service will change after it goes live. The beta Web service will be available after the Web service goes live. You need to ensure that the Windows application can switch between the beta version and the live version of the Web service, if required. You need to achieve this goal by using the least maintenance and coding effort.
What should you do?

A.
Save the URL in the code. Change and recompile the Windows application after switching between the beta and the live versions.

B.
Save the URL in the Windows application configuration file. Update the Web service proxy class.

C.
Save the URL in a resource file. Update the Web service proxy class.

D.
Add a discovery document to the Web service.