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
Froments sign is seen in 
Select and explain. 
A. Ulnar nerve palsy, B. Median nerve palsy, C. Anterior interosseous nerve palsy, D. Radial nerve palsy
A: Ulnar nerve palsy
Answer: A: Ulnar nerve palsy 
Explanation: Froments sign, or the book test tests the adductor pollicis muscle. When the patient is asked to grasp a book firmly between the thumbs and other fingers of both hands, the terminal phalanx of thumb on the paralysed side becomes flexed at the interphalangeal joint (by the flexor pollicis longus which is supplied by median nerve)