X-ray photography PPT of humerus

There is a radial nerve groove at the posterior side of the middle and lower humeral shaft 1/3, and the fracture here is prone to radial nerve injury, which is manifested as: wrist joint, metacarpophalangeal joint can not be straightened, thumb can not be straightened, forearm supination is hindered, and the skin on the radial side of the back of the hand is reduced or disappeared. So the answer is C.