Vehicles for persons with reduced mobility, if there is no road or part of it specially designated for them...

Vehicles for persons with reduced mobility, if there is no road or part of it specially designated for them...
A)may travel on a motorway (autopista).
B)may travel on a dual carriageway (autovía).
C)must travel on the hard shoulder, provided it is passable and sufficient.Correct
This type of vehicle, as it cannot reach a high speed, must travel on the hard shoulder, provided it is passable and sufficient. If not, they shall travel on the right, using only the essential part of the carriageway.
They are completely prohibited from travelling on motorways (autopista) and dual carriageways (autovía), as they cannot reach the minimum required speed of 60 km/h.