You are creating a Windows Workflow Foundation (WF) custom activity by using Microsoft .NET Framework 3.5. The custom activity is derived from the System.Workflow.Activities.SequenceActivity class. You need to create a validator for the custom activity. You also need to ensure that the validator reuses the validation logic provided by WF to recursively validate child activities. Which base class should you use?
A.
ActivityValidator
B.
ConditionValidator
C.
CompositeActivityValidator
D.
DependencyObjectValidator