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
Flexor pollicis longus is supplied by - 
Select and explain. 
A. Ulnar nerve, B. Anterior interosseus nerve, C. Posterior interosseus nerve, D. Radial nerve
B: Anterior interosseus nerve
Answer: B: Anterior interosseus nerve 
Explanation: None