Which of the following is a safety rule?

Answer: A — Follow the speed limit

Following the speed limit is a safety rule as it ensures that you are driving at a safe and controlled speed, reducing the risk of accidents. While B and C may also contribute to safety, they are not universally applicable in all driving situations. Coming to a complete stop may not always be necessary or safe, and driving with windows up may not be necessary in certain weather conditions. Option D is also not a safety rule as it promotes tailgating and not paying attention to other potential hazards on the road. It is important to follow all traffic laws and signs, but also to use common sense and adjust your driving behavior based on the current driving conditions.