What should you do if your vehicle breaks down on the highway?

Answer: B — Stay in your vehicle and call for assistance

Staying in your vehicle and calling for assistance is the safest action to take if your vehicle breaks down on the highway. This choice prioritizes your safety, as the highway can be a dangerous environment with fast-moving traffic. Remaining inside your vehicle protects you from potential accidents, while waiting for help ensures that you are not exposed to roadside hazards. Additionally, staying in your vehicle makes it easier for roadside assistance or emergency services to locate you. They are more likely to see your vehicle on the side of the road than if you are walking for help. Overall, this approach minimizes risk and maximizes the chance of receiving timely assistance.