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. For interactive and self-paced preparation of exam 70-513, try our practice exams. Practice exams also include self assessment and reporting features!
	C. On the client, create a proxy derived from DuplexClientBase(Of TChannel).
	D. On the client, use GetCallbackChannel(Of T).
 
                            