Which of the following must you obey over the other three?

Answer: B — Police officer

The correct answer is that you must obey a police officer over traffic signs, traffic lights, and road markings. This is because a police officer has the authority to direct traffic and enforce the law in a way that overrides standard traffic regulations. Their instructions may take priority in situations where safety is a concern, such as during an emergency or road construction. For example, even if a traffic light indicates to stop, if a police officer is directing vehicles to proceed through an intersection, their command takes precedence to ensure the smooth flow of traffic and enhance safety. This authority has been established to address unique situations that cannot be managed merely by following static traffic controls. In contrast, traffic signs, traffic lights, and road markings are designed to provide guidance to all drivers under normal conditions but do not carry the same immediate authority as a law enforcement officer directing traffic in specific circumstances.