The rules concerning lights shall be complied with in all weathers from sunset to sunrise. The lights _____________.

The correct answer emphasizes that lights must be displayed in restricted visibility during daylight hours, underscoring the importance of maintaining visibility for safety on the water. This is crucial because vessels must be able to see each other even in conditions where visibility is diminished, such as fog, rain, or heavy winds. Displaying lights in these conditions helps prevent collisions and promotes safe navigation.

The requirement to keep lights on in reduced visibility reinforces the fundamental principle that safety on the water is paramount, regardless of the time of day. This means that even during daylight, when visibility might seem sufficient, there can be situations where visibility is significantly impaired, necessitating the use of lights to signal the vessel's presence effectively to others.

In contrast, the other options imply scenarios where the use of lights may not be necessary or where they could be diminished, which does not align with the safety regulations aimed at ensuring that all vessels remain visible and identifiable to each other at all times, especially during adverse weather conditions. Thus, the answer highlights the critical nature of compliance with lighting regulations for safety at sea.