You are modifying a Windows Communication Foundation (WCF) service that allows
customers to update financial data. The service currently requires a transaction from the
client application and is working correctly. The service contract is defined as follows. (Line
numbers are included for reference only.) The service must be modified so that client
applications do not need to initiate a transaction when calling the operation. The service
must use the client application’s transaction if one is available. Otherwise it must use its
own transaction. You need to ensure that the service operation is always executed within a
transaction. What should you do?

A.
OPTION D

B.
OPTION A

C.
OPTION B

D.
OPTION C