<prompt> The ape-thumb deformity occurs due to lesion of:Radial nerveMedian nerveUlnar nerveMusculocutaneous nerve  <response>: Ans. B. Median nerveThe ape-thumb deformity is lack of ability to abduct and oppose the thumb due to paralysis of the thenar muscles. It can occur with an injury of the median nerve either at the elbow or the wrist, impairing the thenar muscles and opponents pollicis muscle. 