What must you do at a railroad crossing when flashing lights are active?
Answer: C — Continue if no whistle is heard.
When flashing lights are active at a railroad crossing, you must stop and not cross. The lights warn that a train could be approaching or may be very near, and trains can be closer than they appear. Wait until the lights stop flashing and the crossing is completely clear before proceeding, then cross only when you can confirm there’s no train in either direction. The absence of a whistle does not make it safe to go, and attempting to honk and rush across is dangerous and illegal.