This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
Structure passing deep to flexor retinaculum at wrist: 
Select and explain. 
A. Ulnar nerve, B. Median nerve, C. Radial nerve, D. Ulnar aery
B: Median nerve
Answer: B: Median nerve 
Explanation: The flexor retinaculum stretches across the front of the wrist and conves the concave anterior surface of the hand into an osteofascial tunnel, the carpal tunnel, for the passage of: The median nerve Flexor tendons of the thumb (flexor pollicis longus and fingers) (flexor digitorum superficialis and profundus). Radial and the ulnar bursa It is attached medially to the pisiform bone and the hook of the hamate and laterally to the tubercle of the scaphoid and the trapezium bones. The attachment to the trapezium consists of superficial and deep pas and forms a synol-lined tunnel for passage of the tendon of the flexor carpi radialis. The lower border is attached to the palmar aponeurosis.