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
All of the following bones are involves in wrist joint formation; except: 
Select and explain. 
A. Scaphoid, B. Ulna, C. Radius, D. Triquetral
B: Ulna
Answer: B: Ulna 
Explanation: Ans. b. UlnaWrist Joint (Radiocarpal Joint)It is a synol ellipsoid joint.It is formed by aiculation of the distal end of the radius and the aicular disc above and the scaphoid, lunate, and triquetral bones below.Ulna excluded from the wrist joint by the aicular disc.