An operation must publish a message only if a database write succeeds, with no possibility of one without the other. Which pattern applies?

1. A Service Bus transactions across the database and broker
2. ✓ B The transactional outbox pattern with a relay reading the outbox (correct answer)
3. C Duplicate detection
4. D Auto-forwarding

Shortcut: Service Bus transactions cannot span an external database. The outbox pattern writes the message into the same database transaction, then a relay publishes it, guaranteeing consistency.