You are developing a Windows Communication Foundation (WCF) service that allows customers to update financial data.
The service contract is defined as follows. (Line numbers are included for reference only)
01 [ServiceContract]
02 public interface IDataUpdate
03 {
04 [OperationContract]
05 [TransactionFlow(TransactionFlowOption.Mandatory)]
06 void Update(string accountNumber, double amount);
07 }
08
09 class UpdateService : IDataUpdate
10 {
11 [OperationBehavior(TransactionScopeRequired = true, TransactionAutoComplete = false)]
12 public void Update(string accountNumber, double amount)
13 {
14 ...
15 }
16 }
17
You need to ensure that the service is invoked within the transaction.
What should you do?（）

You develop a Windows Communication Foundation (WCF) service. You enable all performance counters and run multiple calls to the service.The service must isolate session data to each user. You need to monitor the instancing behaviour used in the service.
Which performance counter should you monitor?（）