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A
Stare at the oncoming headlights to gauge distance
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B
Look slightly to the right toward the edge of your lane
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C
Flash your high beams to retaliate
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D
Close one eye until the vehicle passes
Why this is the answer
When meeting an oncoming vehicle at night with headlights that are blinding you, look slightly down and to the right, toward the right edge of the road or the right shoulder line. This protects your night vision from the direct glare and lets you use the road edge as your steering reference until the vehicle passes. Staring directly at oncoming headlights causes temporary blindness that can last several seconds after the vehicle passes, which is plenty of time to drift out of your lane. Flashing your high beams to retaliate blinds the oncoming driver and creates real danger for both of you. Closing one eye is a partial trick used historically, but is unreliable and not recommended. Keep both eyes open and use the right edge as a guide.
Source: FMCSA CDL Manual 2.7.2 Night Driving Procedures