What does the term 'zero message' refer to in this context?

• A. No messages are ever created
• B. The DLQ is disabled
• C. Achieving zero messages in transit during failure through the reliability pattern
• D. The system processes everything instantly

Answer: (C)

The main idea is the Zero Message In Transit concept: when a failure happens, there are no messages left being processed or in flight. This is a reliability pattern goal—you ensure a message is either fully processed and acknowledged, or not consumed at all, so nothing is partially processed or lost. That’s why the best description is achieving zero messages in transit during failure through the reliability pattern.

The other options don’t capture this idea: nothing about messages never being created, disabling the DLQ isn’t about the in-flight state, and “everything is processed instantly” isn’t related to handling in-flight messages during failures.