Which may be the probable cause of failure?

A service interacts with a backend System which replies with a message correlation. When processing request/response messages from the backend, no messages were received by the flow.

Which may be the probable cause of failure?
A . The transaction was set to automatic on the MQOutput Node.
B . The developer should have used the MQlnput Node instead of the MQGet Node.
C . The Integration Node is configured in a MQ cluster for load balancing and the object descriptor is set to the ReplyToQueueManager.
D . The backend request/reply message processing can only be accomplished by breaking up the flow into two flows.

Answer: D