What can you use to watch for rough spots in the road?

Using the tail lights of the vehicle in front of you is a practical method for monitoring road conditions, especially when visibility may be limited. When you're driving a moped or any vehicle behind another, the tail lights can serve as a clear indicator of what's ahead. If the vehicle suddenly slows down or comes to a halt, it could suggest that there are rough spots, potholes, or obstacles in the road. Keeping an eye on these lights allows you to react promptly and adjust your speed or position, enhancing your safety on the road.

The other options, while they have their uses in different contexts, do not provide the same level of situational awareness as following the vehicle in front of you. A flashlight and a headlamp are primarily tools for visibility, best used in darkness or in specific tasks, but they may not offer the necessary indication of road conditions while you are in motion. The mention of a "shining smile" is clearly light-hearted and not a practical method for assessing road conditions whatsoever.