How far must stop lights be visible from?

Answer: C — 100 feet

The requirement for stop lights to be visible from a distance is important for ensuring drivers have adequate time to respond to traffic signals safely. According to traffic regulations, stop lights must be visible from at least 100 feet away. This distance provides drivers with enough warning to prepare to stop, especially in situations where other vehicles or pedestrians may be present. Visibility from this distance is crucial for the safe flow of traffic and helps reduce the likelihood of accidents. The other options reflect shorter distances, which would not adequately allow for safe stopping distances and reaction times in typical driving conditions.