In case of an emergency, what should assistant conductors do first?

Answer: B — Notify dispatch via emergency communication

In the context of emergency situations, the priority for assistant conductors is to ensure the safety and effective response to the incident. Notifying dispatch via emergency communication is essential because it allows for the coordination of resources, the dissemination of information, and the initiation of emergency protocols. By alerting dispatch, the assistant conductor enables the appropriate emergency services to be informed and dispatched to the scene, which is critical for ensuring that all necessary actions can be taken in a timely manner. This action also helps to create a clear line of communication, ensuring that updates and instructions can be relayed quickly as the situation develops. The correct procedure is rooted in following established protocols that prioritize safety and organized response, which is why this choice stands out as the first action in an emergency scenario.