What is an essential document to check before proceeding after a stop indication is received?

Answer: B — Timetable

Before proceeding after a stop indication is received, it is crucial to check the timetable. The timetable contains critical information regarding train schedules, including the location of stop signals, routes, and any potential restrictions or special instructions related to the train's movement. This ensures that the conductor is fully aware of the operational expectations and any potential hazards or changes in the planned schedule. Having this information is essential for safely resuming travel, as it provides context for the signal encountered and helps to determine the appropriate actions to take. The timetable also aids in coordinating movements with other trains to prevent conflicts and ensure compliance with the established railway system protocols. While other documents like the service record, system special instructions, and track condition summary provide valuable information, the timetable is specifically tailored to guide movement after a stop signal, making it the most relevant document in this scenario.