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
[{'content': "Bennett's fracture is fracture dislocation of base of metacarpal : \nSelect and explain. \nA. 4th, B. 3rd, C. 2nd, D. 1st", 'role': 'user'}, {'content': "Answer: D \nExplanation: Benett's fracture is an intra - articular fracture dislocation of the palmar base of first metacarpal bone of the thumb with either subluxation or dislocation of first carpometacarpal joint, i.e. trapezometacarpal joint.", 'role': 'assistant'}]