【单选题】You are developing a Windows Communication Foundation (WCF) service that contains the following service contract.[ServiceContract( )]public interface IPaymentService{ [OperationContract( )] void Recor...
A.
Add the following KnownType attribute to the Employee class and to the Customer class. [KnownType(GetType(Person))]
B.
Implement the IExtensibleDataObject interface in the Person class.
C.
Implement the IExtension(ofType(T)) interface in the Person class.
D.
Add the following KnownType attributes to the Person class. [KnownType(GetType(Employee))] [KnownType(GetType(Customer))]