What action should be taken when driving at night?

When driving at night, it is crucial to ensure that your headlights are functioning properly and to adjust your speed according to visibility conditions. Nighttime driving presents unique challenges, such as reduced visibility and the potential for encountering pedestrians or animals that may not be easily seen. Properly functioning headlights allow you to see the road and any obstacles clearly, while adjusting your speed ensures that you have enough time to react to any unexpected situations. This combination helps to enhance safety for yourself and others on the road.

Driving with headlights off can impair visibility significantly, while maintaining a high speed is dangerous due to poor visibility. Similarly, using fog lights consistently at all times — especially when they are not needed — can cause glare for other drivers and is often against regulations, contributing to further safety hazards. Therefore, option A is the most responsible action to take when driving during nighttime.