This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Muscles of arm and forearm region & Cubital fossa, Subject name: Anatomy
A 16-year-old boy fell from a motorcycle, and his radial nerve was severely damaged because of a fracture of the midshaft of the humerus. Which of the following conditions would most likely result from this accident? 
Select and explain. 
A. Loss of wrist extension leading to wrist drop, B. Weakness in pronating the forearm, C. Sensory loss over the ventral aspect of the thumb, D. Inability to oppose the thumb
A: Loss of wrist extension leading to wrist drop
Answer: A: Loss of wrist extension leading to wrist drop 
Explanation: Injury to the radial nerve results in: Loss of wrist extension - wrist drop. The median nerve innervates the: Pronator teres, Pronator quadratus, Opponens pollicis muscles and Skin over the ventral aspect of the thumb. The ulnar nerve innervates the dorsal interosseous muscles, which act to abduct the fingers.