Why should you replace a scratched helmet visor?

You answered correctly because a scratched helmet visor should be replaced for two main reasons according to German traffic safety rules: first, scratches can restrict your vision by causing distortions or blurring, which makes it harder to see clearly; second, scratches increase glare from sunlight or headlights, which can temporarily blind you or reduce visibility. Both factors significantly reduce safety by impairing your ability to see the road and other traffic clearly. The third option about misting up is not directly related to scratches but more to the visor's ventilation and anti-fog properties. Therefore, replacing a scratched visor helps maintain clear and safe vision while riding.