This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Upper Extremity, Subject name: Anatomy
A 48-year-old female court stenographer is admitted to the orthopedic clinic with symptoms of carpal tunnel syndrome, with which she has suffered for almost a year. Which muscles most typically become weakened in this condition? 
Select and explain. 
A. Dorsal interossei, B. Lumbricals III and IV, C. Thenar, D. Palmar interossei
C: Thenar
Answer: C: Thenar 
Explanation: The thenar muscles (and lumbricals I and II) are innervated by the median nerve, which runs through the carpal tunnel. The carpal tunnel is formed anteriorly by the flexor retinaculum and posteriorly by the carpal bones. Carpal tunnel syndrome is caused by a compression of the median nerve, due to reduced space in the carpal tunnel. The carpal tunnel contains the tendons of flexor pollicis longus, flexor digitorum profundus, and flexor digitorum superficialis muscles. The dorsal interossei, lumbricals III and IV, palmar interossei, and hypothenar muscles are all innervated by the ulnar nerve.