Which of the following code statements should you insert at the beginning of the above mentioned code segment?

You work as an Application Developer for PassGuide.com. You have been assigned to create a
WCF service for the Business School of Management. You write the following code segment to
define the service:
Public Interface ISchoolService
<OperationContract()>
Sub FindStudent(int StudentID)

End Interface
Public Class School
Implements ISchoolService
<OperationBehavior(TransactionAutoComplete:=False, TransactionScopeRequired:=True)
>
Public Sub FindStudent(int studentnumber)
End Sub
End Class
Your next task is to set the <ServiceContract> attribute for the transaction behavior of this service.
Which of the following code statements should you insert at the beginning of the above mentioned
code segment?

A.
<ServiceContract(SessionMode:=SessionMode.Required)>

B.
<ServiceContract(SessionMode:=SessionMode.NotAllowed)>

C.
<ServiceContract(SessionMode:=SessionMode.Permitted)>

D.
<ServiceContract(SessionMode:=SessionMode.Allowed)>

Explanation: