Injury to radial nerve in lower pa of spiral groove result in which of the following?

Ans:B.)Results in paralysis of anconeus muscle.RADIAL NERVE(1) Before entering the spiral groove, radial nerve supplies the long and medial heads of the triceps.(2) In the spiral groove, it supplies the lateral and medial heads of the triceps and the anconeus. (3) Below the radial groove, on the front of the arm, it supplies the brachialis with proprioceptive fibres, the brachioradialis, and the extensor carp radialis longus.The radial nerve is very commonly damaged in region of the radial (spiral) groove. The common causes of injury are: (i) intramuscular injections in the arm (triceps), (ii) sleeping in an armchair with the limb hanging by the side of the chair (Saturday night palsy), or even the pressure by crutch (crutch paralysis), and (iii) fractures of the shaft of the humerus. This results in the weakness or loss of power of extension at the wrist (wrist drop) and sensory loss over a narrow strip on the back of forearm, and on the lateral side of the dorsum of the hand.