Option "D" is the correct answer: A narrow road is not considered a visibility condition. Considering that visibility is a distance measure at which an object or light can be clearly discerned depending upon the surface weather conditions, it may be affected by fog, smoke, haze, and mist among others. Not only haze and smoke, but also fog and mist which are composed mainly of water droplets, may cause low visibility. When this happens, roads may be closed, or automatic warning lights and signs may be activated to warn drivers.