When can drivers use "high-beam" headlights?

Answer: C — In darkness or rural areas when no oncoming traffic is present

High-beam headlights are designed to illuminate a greater distance than low-beam headlights, making them particularly useful in darkness or rural areas where there is little to no ambient light from streetlights or other sources. The correct use of high-beam headlights is primarily when there is no oncoming traffic present, as using them in the presence of other vehicles can blind drivers due to the intensity of the light they emit. Options that suggest using high-beam headlights in urban areas with streetlights or during daylight hours are not appropriate because the added brightness of high beams is unnecessary and can cause glare for other drivers. Furthermore, using high beams while driving in rain or fog is not advisable, as the light can reflect off the moisture in the air, creating a glare that reduces visibility rather than improving it. Thus, the conditions under which high beams should be used are specifically when driving in dark or rural areas and ensuring that no other vehicles are present to maintain safety for all road users.