An on-premise application is exposed to external users through a Windows Communication Framework （WCF） service endpoint registered in the Windows Azure AppFabric Service Bus.  You need to recommend an approach for providing transport-level security that maximizes performance and minimizes bandwidth requirements.  What should you recommend？（）

• A、 Use reliable messaging.  Use HTTP for message delivery.
• B、 Use binary message encoding.  Use TCP for message delivery.
• C、 Use Plain Old XML （POX） messages.  Use TCP for message delivery.
• D、 Use Message Transmission Optimization Mechanism （MTOM） message encoding. Use HTTPS formessage delivery