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
[{'content': 'Pt carpometacarpal joint is a type of ? \nSelect and explain. \nA. Ellipsoid, B. Saddle, C. Condylar, D. Ball and socket', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Saddle", 'role': 'assistant'}]