You create a Windows Workflow Foundation application by using Microsoft .NET Framework 3.5. The application uses a sequential workflow.

The host application creates a workflow instance and stores it in a variable named instance. When the workflow is executed, a business requirement requires the workflow execution to pause for a few minutes.
The host uses the following code segment.

WorkflowRuntime runtime = new WorkflowRuntime();
WorkflowInstance instance =
runtime.CreateWorkflow( typeof(Workflow1));
instance.Start();

You need to ensure that the following requirements are met:

The workflow execution is temporarily paused.
The workflow state is preserved in memory.

Which line of code should you use?

A.
instance.Unload();

B.
instance.TryUnload();

C.
instance.Suspend(null);

D.
instance.Terminate(null);