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': 'True regarding mallet finger is : \nSelect and explain. \nA. Avulsion of tendon at the base of the middle phalanx, B. Avulsion of extensor tendon at the base of the distal phalanx, C. Fracture of distal phalanx, D. Fracture of the proximal phalanx', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Mallet finger is avulsion of extensor tendon from distal phalanx of a finger.', 'role': 'assistant'}]