What action must a driver take at a red traffic light?

Answer: B — Come to a complete stop and wait for it to turn green

When a driver approaches a red traffic light, the correct action is to come to a complete stop and wait for the light to turn green. This rule is crucial because red lights are signals for all vehicles and pedestrians to stop, ensuring safety and order on the road. By stopping, drivers allow cross traffic to clear and help prevent accidents. While it may be permissible in some jurisdictions to make a right turn on red after a complete stop, drivers must first stop completely and assess their surroundings, which is why the other answer about making a right turn can be misleading if not properly contextualized. The requirement to stop ensures that drivers are prioritizing safety and compliance with traffic laws before proceeding. Therefore, the emphasis is on the complete stop at a red light as the primary and most critical action required from drivers.