Which of the following vehicles are permitted to drive on the road’s “hard shoulders”?

1. A Only taxis, in order to bypass vehicles that stand in an intersection.
2. B No one is allowed, in to use the “hard shoulders”.
3. C Non-motor vehicles, tractors and speed-restricted vehicles.
4. D Only private vehicles and motorcycles are permitted to drive on the “hard shoulder”, and only in order to give right-of-way to buses.