A Windows Communication Foundation (WCF) service has a callback contract. You are developing a client application that will call this service.You must ensure that the client application can interact with the WCF service. What should you do?（）

• A、On the OperationContractAttribute, set the AsyncPattern property value to true.
• B、On the OperationContractAttribute, set the ReplyAction property value to the endpoint address of the client.
• C、On the client, create a proxy derived from DuplexClientBase<TChannel >.
• D、On the client, use GetCallbackChannel<T >.