UK Driving Theory Practice Exam

Fog lights are an additional set of lights on a vehicle that are specifically designed to be used in foggy or other adverse weather conditions. It is important to only use fog lights when the visibility is limited, such as when it is raining heavily or when visibility is less than 100 meters. Using fog lights when they are not necessary, such as during nighttime driving on highways or all the time, can actually create a hazard for other drivers by creating glare and reducing their ability to see. Therefore, option B is the most accurate answer.