What can impair your attention when driving through a tunnel?

You answered correctly. Both reflections of light from oncoming traffic and the length of the tunnel can impair your attention when driving through a tunnel. Bright reflections or glare from headlights can distract or temporarily dazzle your eyes, making it harder to focus on the road. The length of the tunnel can also affect your concentration because longer tunnels may lead to monotony and reduced alertness over time. Good road markings, however, do not impair your attention; instead, they help guide you safely. Understanding these factors helps you stay more alert and safe while driving through tunnels.