After passing an automatic stop signal at ON. If the Driver finds a train or obstruction he must stop his train at ________ away from the train or obstruction. A. 200 meters B. 180 meters C. 150 meters D. None of these

The correct answer is: A. 200 meters

According to the Federal Railroad Administration (FRA), after passing an automatic stop signal at ON, if the Driver finds a train or obstruction, he must stop his train at least 200 meters away from the train or obstruction. This is to ensure that there is enough space for the train to come to a safe stop without colliding with the train or obstruction.

Option B is incorrect because it is not the minimum required distance. Option C is incorrect because it is not the minimum required distance. Option D is incorrect because it is not an option.