フリー問題

問題文

Which option correctly describes how an event travels from an EventSource to a Sensor?

選択肢

1. The EventSource publishes onto the EventBus, and the Sensor subscribes to it.
2. The Sensor polls the external system on the schedule that the EventSource declares.
3. The EventSource opens a connection to the Sensor and delivers the event directly, and the EventBus is an optional component that is only used when several Sensors need the same event.
4. Both write to a shared ConfigMap that the controller watches.