These signs, on a conventional road, indicate a diversion towards...
A)a motorway or dual carriageway.
B)the indicated town.
C)another conventional road.Correct
The signs in the question indicate, on a conventional road, the directions reached via the immediate exit onto another conventional road. They also indicate the direction of the conventional road itself and its number.
Immediate exit signs always display the colour of the road towards which you are heading. White for a conventional road and blue for a motorway or dual carriageway.