Which description best contrasts publish/subscribe with queue-based point-to-point messaging?

• A. Use Pub/Sub for strict one-to-one delivery.
• B. Use Pub/Sub for event-driven decoupling and fan-out; queues for direct task delivery.
• C. Use Pub/Sub when guaranteed order is required.
• D. Use Queue-based for synchronous processing.

Answer: (B)

The main idea tested is how publish/subscribe and queue-based point-to-point messaging handle delivery differently. Publish/subscribe is built for decoupling producers from consumers and broadcasting a message to many subscribers, enabling event-driven patterns and fan-out. In contrast, queue-based point-to-point messaging sends each message to a single consumer, which is ideal for direct task delivery and coordinating work among workers.

That’s why the best description is that publish/subscribe supports event-driven decoupling and fan-out, while queues support direct task delivery. The other statements don’t fit: one-to-one delivery isn’t the hallmark of publish/subscribe, ordering guarantees in publish/subscribe aren’t typically assured across multiple subscribers, and queue-based messaging is usually used for asynchronous task processing rather than strictly synchronous processing.