When driving in fog, it is best to use:

Using low beam headlights when driving in fog is essential for safety. Low beam headlights direct their light closer to the ground and provide adequate visibility without causing glare. In foggy conditions, high beam headlights tend to reflect off the water droplets in the fog, creating a blinding effect that can reduce visibility further rather than enhance it.

Fog lights, while useful, usually work best in conjunction with low beams rather than as a standalone solution. They are designed to provide a wide and flat beam of light that illuminates the road immediately in front, but should not replace low beams entirely. Parking lights do not provide sufficient illumination for safe driving in foggy conditions and are not a suitable choice for navigating through reduced visibility.

Therefore, utilizing low beam headlights offers a balance between visibility for the driver and minimizing the glare that could impair visibility for others on the road.