In which circumstances may we drive with the high-beam headlights on?

In which circumstances may we drive with the high-beam headlights on?
A)Within a built-up area on insufficiently illuminated roads.
B)Outside a built-up area on insufficiently illuminated roads.Correct
C)On insufficiently illuminated through-roads (travesías).
High-beam or main-beam headlights must be used by vehicles equipped with them when driving at more than 40 km/h:
- Between sunset and sunrise, on insufficiently illuminated interurban roads.
- At any time of day, in tunnels, underpasses and stretches of road affected by the Tunnel sign, when insufficiently illuminated.
However, the low-beam or dipped headlights must be used by:
- Vehicles not equipped with high-beam lights.
- Those driving with high-beam lights that may dazzle other road users.
When driving at a speed not exceeding 40 km/h, either low-beam or high-beam lights may be used.
The use of high-beam lights is prohibited when the vehicle is stopped, parked or within a built-up area.
Both answer a) and answer c) refer to urban roads, and the use of high-beam lights is prohibited there.