It is mandatory to complete an overtaking manoeuvre...
A)by returning to the lane gradually without obstructing.Correct
B)only by signalling the lateral movement.
C)by returning to the right lane at the highest possible speed.
The driver of the vehicle that has carried out the overtaking must return to their lane as soon as possible and gradually, without forcing other users to modify their trajectory or speed, and warning them by means of the prescribed signals.