Final answer:
When stopping along the road at night, one should turn on emergency flashers and low beams for safety. Car headlights dim gradually as the battery voltage decreases, a phenomenon also observed in household appliances due to resistance.
Step-by-step explanation:
If you stop along the road at night, the safest option would be to turn on your emergency flashers and leave your low beams on, which corresponds to option C. This ensures that your vehicle is visible to other road users, thereby reducing the risk of an accident. Turning off all lights or only keeping the high beams on can be dangerous, as it makes your vehicle less visible or can dazzle oncoming drivers. Likewise, simply turning on headlights without emergency flashers might not provide a clear signal to others that your vehicle is stationary.
When discussing car lights and battery behavior, one observes that as the car battery runs down, the headlights do not suddenly turn off but instead gradually dim. This happens because the battery output voltage decreases as the battery is depleted. A similar effect is observed in various other instances, such as when a refrigerator's light dims momentarily as the motor starts or when your car's passenger compartment light dims when igniting the engine, which may be attributed to resistance inside the battery itself.