What does Alan Stern say move in a straight line away from the mountains in a sea of nitrogen until they run into something on Pluto?

When approaching an emergency vehicle, law enforcement vehicle, or tow truck stopped on a two-lane road with a speed limit of 20 mph or less, you are required to a. slow down to 10 mph b. slow down to 5 mph c. stop and offer assistance d. pass the vehicle in an opposing lane, if safe