Can a change of direction (U-turn) be made on a conventional road?
A)No, in no case.
B)Yes, if there is no sign prohibiting it.Correct
C)No as a general rule.
A U-turn can be made on a conventional road, as it has a single carriageway for both directions, provided that there are no vertical signs or road markings expressly prohibiting it and the circumstances are favourable.