What equipment helps prevent freight train accidents related to wheel issues?

Answer: B — Hotbox detectors

Hotbox detectors are critical components used in the rail industry to prevent freight train accidents related to wheel issues. These detectors monitor the temperature of bearings on train axles as the train passes over them. When a bearing overheats, it can signify that it is faulty or at risk of failing, which could lead to severe accidents such as derailments. By using hotbox detectors, railroads can identify problematic bearings before they cause accidents, allowing for timely maintenance and repairs. This proactive approach enhances the safety of train operations significantly, as it addresses potential issues before they escalate into serious problems that could jeopardize the safety of the train and its cargo. The other equipment mentioned, while vital for various aspects of train safety and operation, does not specifically address the issue of wheel-related accidents in the same targeted way as hotbox detectors do.