You are developing a new version of an existing message contract named CustomerDetailsVersion1. The new version of the message contract must add a Department field of type String to the SOAP header.You create a new class named CustomerDetailsVersion2 that inherits from CustomerDetailsVersion1. You need to ensure that all client applications can consume the service.
Which code segment should you use?（）

You are developing a Windows Communication Foundation (WCF) client application.
The client application contains the following code.

[ServiceContract]
public interface ISocialStatus
{
[OperationContract]
[WebInvoke(UriTemplate = "/statuses/update.xml?status-{text}")]
void UpdateStatus(string text);
}
public class SocialClient : ClientBase, ISocialStatus
{
...
}
The configuration file contains the following lines.
binding="webHttpBinding" contract="SocialApp.ISocialStatus"
bindingConfiguration="BindingConfig" />
You need to ensure that the service is consumed.
Which code segment should you use?（）