You create a Windows Workflow Foundation application by using Microsoft .NET Framework 3.5. The application uses a sequential workflow. You add an instance of the ParallelActivity class to the workflow to execute two activities simultaneously. The logic for simultaneous execution requires the activities to access a shared variable named count. You need to ensure that the branches of the ParallelActivity class execute until they are complete before the next branch commences.
Which activity should you insert in each branch?

A.
SequenceActivity

B.
TransactionScopeActivity

C.
SynchronizationScopeActivity

D.
CompensatableTransactionScopeActivity