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
Adduction of thumb occurs at: 
Select and explain. 
A. Inter carpal joint, B. MCP joint, C. Carpometacarpal joint, D. Inter phalangeal joint
C: Carpometacarpal joint
Answer: C: Carpometacarpal joint 
Explanation: C i.e. Carpometacarpal joint 1st carpometacarpal joint (cmj) is the only cmj with seperate joint cavity so the movements are much free. Flexion- extension (in the plane of palm), adduction - abduction (at right angles to the plane of palm), opposition & circumduction, movements of thumbQ take place at 1st CM Joint.