On motorcycles, the rider's posture must be...

A)as aerodynamic as possible, bending the body as much as possible.
B)slightly forced, to avoid becoming too relaxed.
C)relaxed and not forced, without bending the body more than necessary.Correct
The posture of a motorcycle rider must be relaxed and not forced, always adapting to the type of motorcycle being ridden, and must allow the controls of the motorcycle to be used without difficulty. In any case, the rider must feel comfortable, without forcing any particular posture.