What should drivers do when halted at railroad crossings at night waiting for a train?

Answer: B — Turn on low-beam headlights

When drivers are halted at railroad crossings at night waiting for a train, turning on low-beam headlights is the appropriate action. This setting provides sufficient illumination of the area without blinding other drivers or making it difficult for the train operators to see the vehicles. Low-beam headlights offer adequate visibility while minimizing glare, ensuring that other road users can maintain awareness of the situation. In contrast, using high-beam headlights can create significant glare that may impair visibility for oncoming drivers and present a risk during a critical moment like waiting at a railroad crossing. Keeping headlights off entirely could lead to being less visible to other vehicles, increasing the risk of an accident. Flashing headlights may confuse other road users or fail to attract attention effectively, thus not being advisable in this scenario.