From when must the Rules concerning lights be complied with?

The rules concerning navigational lights are crucial for ensuring the safety of vessels operating on the water, particularly in conditions where visibility is compromised. Compliance with these rules is required from sunset to sunrise and also during restricted visibility, which includes conditions such as fog, heavy rain, or darkness caused by high hills or other obstructions.

The reason this answer is correct is rooted in the purpose of these rules: to prevent collisions and ensure that vessels can see and be seen by others on the water, particularly in the most dangerous conditions. At night, when natural light does not illuminate the surroundings, the presence of navigation lights becomes essential. Similarly, during periods of restricted visibility, lights help in signaling a vessel's presence, its course, and its state of navigation, thus enhancing safety.

The other options either limit the requirement for lights to just nighttime or exclude important scenarios like restricted visibility, which would not be effective for ensuring navigational safety in all situations. Thus, the comprehensive compliance required during both nighttime and restricted visibility aligns squarely with the principles of maritime safety outlined in the COLREGs.