You are designing a Windows Forms application that allows users to search a product

catalog and place orders. You have the following requirements: • Display a progress
indicator while the application is searching the catalog. • Ensure that users can cancel
search operations. You need to recommend an approach that meets the requirements.
What should you recommend?

A.
Implement the search as a Windows Communication Foundation (WCF) service by using
the AsyncPattern property of the OperationContract attribute.

B.
Implement the search as a duplex service.

C.
Use a BackgroundWorker component to perform the search.

D.
Execute the search on the user interface thread. Provide a Cancel button to cancel the
search.