When is it mandatory to use low-beam headlights during the day?

A)when it is raining.
B)when travelling in an HOV lane.
C)when travelling in a reversible lane.Correct
During the day, motorcycles travelling on any road, whether urban or interurban, must have their low-beam (dipped) headlights on, as must all vehicles travelling on:

- A reversible lane.
- A temporary additional lane, as well as vehicles travelling on hard shoulders.
- A lane enabled for travel in the opposite direction to the usual one, whether a lane exclusively reserved for them or one exceptionally opened to traffic in that direction.
- A normal-direction lane adjacent to one enabled for travel in the opposite direction to the usual one.