You want to enable users of a Web application to modify the Web application's UI and behavior. These modifications must be maintained at the user level so that when users return to the Web application, the changes are still in effect. You need to achieve this goal by using the minimum amount of custom code. What should you do?（）

• A、Persist control data by using view state.
• B、Use Web Part controls.
• C、Maintain a profile for each user.
• D、Enable session state on the Web application.