DRAG DROP
There is a WCF (Windows Communication Foundation) service PassGuideService.
The clients and the service that uses PassGuideService use NetTcpBinding (transaction flow
enabled).
Assuming that the operations PassGuideOP1 and PassGuideOP2 are called within the same
client session, you need to enforce that they are executed within the same transaction context.
Which contract should PassGuideService have?
Answer: 
Explanation: