Damage to which car of Potts’ train would have caused the greatest loss of life?

The correct answer is A) sleeper car.

Explanation: The sleeper car is where passengers sleep during overnight train journeys. If this car were to be damaged, it would likely be filled with people potentially sleeping, leading to a greater loss of life compared to damage to a tank car (which carries liquids), mail car, or baggage car, none of which typically carry passengers.