Following the rule of law refers to obeying an actual law that is implemented in a society. Speed limits are actual laws so when we drive the speed limit, we are following the rule of law.
The other options are not correct because they are not based on actual laws. They are simply based on the civil and environmental responsibilities. There is no law for instance, that forces us to vote or to recycle or to get a driver's license (unless you are driving in which case this is a law).
