What must you do when a school bus has its red lights flashing?

Answer: B — Proceed with caution if you are in the opposite direction.

Red flashing lights on a school bus mean children may be crossing near the bus, so you should slow down and be prepared to stop. The important nuance is the road layout. If you’re traveling in the opposite direction on a divided highway with a physical barrier or median between directions, you’re not required to come to a full stop; you should simply slow and proceed with caution after checking for any children crossing. That’s why this choice is the best: it reflects care and awareness in the specific divided-highway situation. If there’s no divider, or if you’re in the same lane as the bus, the rule is to stop.