Where are stops prohibited for loading or unloading students?

Answer: B — Within 200 feet of a railroad crossing

Stops for loading or unloading students are prohibited within 200 feet of a railroad crossing primarily due to safety considerations. This regulation is in place to ensure that students are kept at a safe distance from trains, which can approach quickly and quietly. The area near a railroad crossing can have limited visibility and may be hazardous if a vehicle is stopped there. Keeping the bus and students away from these crossings helps to minimize the risk of accidents, ensuring that children can load and unload safely without the added dangers of nearby train traffic. The other options, while they may have specific implications for traffic safety, do not carry the same level of urgency related to the unique hazards presented by railroad crossings. For instance, stopping near a traffic light or on the highway may create traffic issues, but they do not typically have the same risks associated with railroad operations. Stopping in parking lots, while it could present other safety concerns, is generally allowed unless it creates additional hazards for students.