You are developing a Windows Communication Foundation (WCF) service. The service operation takes a customer number as the only argument and returns information about the customer. The service…

You are developing a Windows Communication Foundation (WCF) service. The service operation takes a customer number as the only argument and returns information about the customer. The service requires a security token in the header of the message. You need to create a message contract for the service. Which code segment should you use?