Answer:
A: If visibility is reduced by fog or snowfall. The use of fog lights and low-beam headlights is permitted in daylight when visibility is reduced due to fog or snowfall to improve the driver's visibility and prevent accidents.
Step-by-step explanation:
The use of fog lights and low-beam headlights is permitted in daylight when visibility is reduced by fog or snowfall. Therefore, the correct answer is "a) If visibility is reduced by fog or snowfall." Fog lights and low-beam headlights can help increase visibility in adverse weather conditions and reduce the risk of accidents. It is important to note that using high-beam headlights in foggy conditions can actually reduce visibility and should be avoided.