Must a vehicle immobilised due to breakdown on the hard shoulder be signalled?

Must a vehicle immobilised due to breakdown on the hard shoulder be signalled?
A)No, because the vehicle is not on the carriageway.
B)No, because the place used to immobilise it is the appropriate one for that type of situation.
C)Yes, with the vehicle's hazard warning lights, the pre-warning hazard triangles and, where applicable, the position lights.Correct
When immobilising a vehicle on the hard shoulder due to a breakdown, it is mandatory to signal it to warn other users of the danger. To do so, the hazard warning lights must be activated and the pre-warning hazard devices (triangles) must be placed. Additionally, if it is night-time or visibility is reduced, the position lights must also be switched on.