Final answer:
The correct answer is b. drive at the posted speed. When the common speed on the expressway is above the posted speed limit, it is important to drive at the posted speed. By doing so, you are following the law and reducing the risk of accidents or collisions.
Step-by-step explanation:
The correct answer is b. drive at the posted speed.
When the common speed on the expressway is above the posted speed limit, it is important to adhere to the posted speed limit. The posted speed limit is set for the safety of all drivers on the road, taking into account factors such as road conditions, traffic volume, and potential hazards. By driving at the posted speed, you are following the law and reducing the risk of accidents or collisions.
For example, if the posted speed limit is 65 mph and the common speed is 75 mph, it would be best to drive at 65 mph to ensure safe and legal driving.