In addition to the corresponding light signals, reversing may also be indicated with the arm...
A)moving it up and down.
B)bent upward, with the hand extended.
C)extended horizontally with the palm of the hand facing rearward.Correct
If we do not have a reversing light, we shall signal it with the left arm extended with the palm of the hand facing rearward.
In the event of a contradiction between the vehicle's light signal and the signal given by the driver with their arm, we must obey the driver, as the light signal may be faulty.
As a general rule, reversing is prohibited, except in the following cases on an exceptional basis and always covering the minimum indispensable distance:
1. As a complementary manoeuvre to stopping, parking, or joining the flow of traffic. In this case, the reversing distance may not exceed 15 metres nor encroach upon a road junction.
2. When it is not possible to move forward or to change direction or sense of travel. In this case there is no limit on the reversing distance, even allowing encroachment upon a road junction if necessary.
The reversing manoeuvre is prohibited on dual carriageways and motorways.