Which statement regarding school buses approaching railroad crossings is true?

The statement that school buses need not stop when traveling in a convoy and the first bus already stopped is true because regulations often allow for a waiver of the stop requirement at railroad crossings in situations where multiple vehicles are traveling closely together, like in a convoy. When the lead bus stops and confirms the crossing is clear, the following buses are not required to stop again, as it is assumed they would be following the lead bus's example.

While other statements may present aspects of railroad safety, they do not accurately reflect the specific rules regarding school buses traveling in a convoy. For instance, buses stopping every time would not account for situations where it's safe to proceed, and yielding to railroad signals is generally a practice applied to all vehicles, not specifically tailored to the circumstances of a school bus convoy. The option regarding sounding the horn before proceeding does not comply with safety protocols, as the primary requirement is to stop and ensure safety at railroad crossings.