Which statement about nighttime headlight use is correct?

Answer: C — Dim to low beams within 500 feet of an oncoming vehicle

When driving at night, you should switch from high beams to low beams whenever an oncoming vehicle is in your headlights’ path at a distance where your high beams could dazzle them. This keeps the other driver from being blinded while still giving you enough light to see the road ahead. This rule matches the standard safety practice: dim to low beams before your headlights would shine directly into the oncoming driver’s eyes. Dimming earlier than necessary reduces your own visibility without extra safety benefit, while dimming too late can cause glare for the other driver. The other distance descriptions don’t align with this balance of protecting the other driver and maintaining adequate visibility for you.