You create a Windows Workflow Foundation application by using Microsoft .NET Framework 3.5.

The workflow design is as shown in the following exhibit. (Click the Exhibit button.)

You need to add an activity before the throwActivity1 activity. You also need to ensure that the added activity allows the throwActivity1 activity to throw an exception only if the Approved event is not received in four hours.

What should you do?

A.
Add a DelayActivity activity and set the TimeoutDuration property to four hours.

B.
Add a CodeActivity activity. In the CodeActivity activity, call the Thread.Sleep method. Pass a time span of four hours to the Thread.Sleep method.

C.
Add a CodeActivity activity. In the CodeActivity activity, instantiate a Timer class. Set the Interval property of the Timer class to four hours. Handle the Elapsed event and check if the event has been raised.

D.
Add a WhileActivity activity. In the WhileActivity activity, add a SuspendActivity activity. In the Condition property of the WhileActivity activity, create a code condition and attach a delegate to the Approved event in the workflow.