When passing a large vehicle, when is it safe to pull back in front of the truck?

The correct answer is based on a key principle of safe driving around large vehicles. When you can see the headlights of the truck in your inside rearview mirror, it indicates that you have successfully cleared the vehicle and that it is safe to maneuver back into your lane. This visual confirmation is crucial because large trucks have longer stopping distances and blind spots that can make it difficult for them to see smaller vehicles.

By focusing on the headlights in your rearview mirror, you ensure that the truck is sufficiently behind you, reducing the risk of inadvertently cutting it off or entering its blind spot. Additionally, this technique provides you with the information needed to assess the speed and distance of the truck relative to your own vehicle, helping maintain safety on the road.

Other options might suggest cues that are less reliable, such as just finishing the passing maneuver without a proper assessment of the truck's position or speed, or even ambiguous indicators like seeing the truck's front bumper, which may not guarantee safe distance.