<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 43-year-old woman comes to the physician because of tingling and weakness in her left arm for the past 2 days. An image of the brachial plexus is shown. Nerve conduction study shows decreased transmission of electrical impulses in the labeled structure. Physical examination is most likely to show impairment of which of the following movements?? A: Extension of the wrist and fingers, B: Opposition of the thumb, C: Flexion of the metacarpophalangeal joints, D: Flexion of the forearm, E: Abduction of the shoulder above 100 degrees,  <response>: This is a clinical vignette describing a 43-year-old woman with tingling and weakness in her left arm. The image shows the brachial plexus, which is a network of nerves that supplies the upper extremity. Nerve conduction studies show decreased transmission in the structure labeled, which appears to be the posterior cord of the brachial plexus based on the image. The posterior cord gives rise to the radial nerve, so impairment would affect movements supplied by the radial nerve. The radial nerve innervates muscles that extend the wrist and fingers, so choice A Extension of the wrist and fingers is likely to be impaired. Choices B through E describe movements innervated by other nerves that would be unaffected by damage to the posterior cord.A: Extension of the wrist and fingers 