You are creating a Windows Communication Foundation (WCF) service. You do not want to expose the internal implementation at the service layer. You need to expose the following class as a service…

You are creating a Windows Communication Foundation (WCF) service. You do not want to expose the internal implementation at the service layer. You need to expose the following class as a service named Arithmetic with an operation named Sum:

public class Calculator { public int Add(int x, int y) { } } Which code segment should you use?