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: Orthopaedics
Injury to the Ulnar nerve at the wrist causes paralysis of- 
Select and explain. 
A. Apposition of the thumb, B. Abduction of the carpo-metacarpal joint of the thumb, C. Adduction of the thumb, D. Flexion of the MCP joint of the middle finger
C: Adduction of the thumb
Answer: C: Adduction of the thumb 
Explanation: Adduction of thumb is lost due to paralysis of adductor pollicis.