This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hand Injuries, Subject name: Orthopaedics
[{'content': 'Which of the following is true regarding mallet finger? \nSelect and explain. \nA. Also known as Badminton finger, B. Rupture of extensor tendon, C. Contraction deformity of flexor tendon, D. Treatment is Open reduction and internal fixation', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Rupture of extensor tendon * Mallet finger Has been explained in previous sessions", 'role': 'assistant'}]