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': 'Mallet finger is due to avulsion of extensor tendon of- \nSelect and explain. \nA. Proximal phalanx, B. Middle phalanx, C. Distal phalanx, D. Metacarpals', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]