What is true about errors inside an async scope?

• A. The main flow waits for the async scope to complete before continuing
• B. The response from the async scope is NOT accessible to the main flow
• C. Async scope runs sequentially relative to the main flow
• D. Errors inside the async scope do not impact the main flow

Answer: (B)

Asynchronous processing runs on a separate thread, so the main flow doesn’t wait for the async scope to finish. Because of that parallel execution, the result produced inside the async scope isn’t automatically available to the main flow. In Mule, the main flow continues with its own message path, and the payload or data created inside the async block isn’t exposed unless you explicitly pass it back through a continuation path, a flow reference, or by updating a shared data location before exiting the async scope. This is why the statement about the async scope’s response not being accessible to the main flow is true.