As a general rule, manoeuvres must be signalled using...
A)preferably the arm.
B)either the arm or light signals interchangeably.
C)preferably the vehicle's light signals.Correct
As a general rule, to warn other road users of a manoeuvre, we must indicate it with sufficient advance notice, using the vehicle's light signals (which must remain on for the entire duration of the manoeuvre) and, failing that, with the arm (to be valid they must be performed correctly and be visible). In the event of contradiction, the signal made with the arm takes precedence.
Arm signals are as follows:
Arm signals are as follows: