You are designing a Windows client application by using Microsoft NET Framework 4 and Microsoft Visual Studio 2010. The business logic layer of the application is implemented by using Windows Communication Foundation (WCF). You write the following code segment in the middle tier:
<ServiceContractO> —
Public Interface lWcf Service
<OperationContractO> —
<FaultContract(GetType(ApplicationException))> —
Sub ProcessData(ByVal d As Data)
End Interface

The Process Data service method is a long-running operation. You need to ensure that the application meets the following requirements:
+ Users can continue to use the user interface while the Process Data service method is running.
+ Message delivery is reliable.

What should you use?

A.
A Session full One-Way operation on Process Data with a proxy-based synchronous class invocation

B.
A Session full Request-Reply operation on Process Data with a proxy-based asynchronous invocation

C.
A Session less One-Way operation of Process Data with a proxy-based synchronous class invocation

D.
A Session less Request-Reply operation on Process Data with a proxy-based asynchronous invocation