When must vehicle lights be turned on in relation to highway visibility?

Answer: B — 400 feet from sunset to sunrise

The requirement to turn on vehicle lights from sunset to sunrise is grounded in safety laws that aim to ensure drivers are visible to others during times of reduced visibility. The law specifies a distance of 400 feet to adequately alert vehicles and pedestrians in the surrounding environment that a vehicle is approaching. This is particularly critical during darker hours when the risk of accidents increases significantly due to the limited range of vision. In this context, while the other options mention important considerations for vehicle lighting, they do not reflect the specific legal standards. Turning on lights 300 feet at all times is not consistent with the established regulations for nighttime driving. The mention of 500 feet during inclement weather is usually suggested in general safety practices, but not stipulated in the same way as the requirement for night driving specifically. Suggesting that lights should be on only during storms overlooks the broader requirement of ensuring visibility during all times of low light, emphasizing safety during typical night conditions, not just severe weather situations.