You are creating a workflow by using Microsoft .NET Framework 3.5. You use Windows Workflow Foundation to create the workflow. You need to create a custom activity for the workflow that must not manage any child activity. Which base class should you use?

A.
System.Workflow.Activities.StateActivity

B.
System.Workflow.ComponentModel.Activity

C.
System.Workflow.Activities.SequenceActivity

D.
System.Workflow.Activities.SequentialWorkflowActivity