Which of the following describes what a marker for the point at which a 10-car train may resume normal speed indicates?

The marker indicating the point at which a 10-car train may resume normal speed signifies the position where the train can safely return to its full operational speed after a period of reduced speed. This is essential for maintaining safe and efficient train operations, particularly in situations where the train may have had to slow down due to track conditions, signals, or other operational requirements.

Once the train reaches this marker, it confirms that any restrictions in place have been lifted, and the train can accelerate back to its maximum permitted speed. This ensures that train operators understand where they can safely increase their speed without compromising safety or operational standards.

The other options, while related to speed regulations and train operations, do not accurately describe the specific function of the marker in question. Understanding this marker is crucial for train operators who must adhere to speed regulations to ensure safe travel on the tracks.