Final answer:
The correct response to when to dim high beams is within 500 feet of an oncoming vehicle and within 300 feet when following a vehicle, which corresponds to option B.
Step-by-step explanation:
The question pertains to the appropriate times to dim high beam headlights when driving near other vehicles. In most areas, you must dim your high beams when you are within 500 feet of an oncoming vehicle and within 300 feet when following behind another vehicle. Therefore, the correct answer is B) 500, 300.