You are conducting an architectural review of an existing ASP.NET Web application. The
Web application uses only full-page postbacks, which degrades its performance. You have
the following requirements: • Extend existing control by using AJAX functionality. • Reduce
the size of postbacks without modifying the existing controls. You need to recommend an
approach for meeting the requirements. What should you recommend?

A.
Create a user control that implements the IExtenderProvider interface.

B.
Create a server control derived from the ExtenderControl class.

C.
Create a user control that implements the IAsyncActionlnvoker interface.

D.
Create a server control derived from the Substitution class.