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: Dental
[{'content': 'Which of the following is Masochistic habit \nSelect and explain. \nA. Nail biting, B. Digit Sucking, C. Lip biting, D. Gingival stripping', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Classification of Habits', 'role': 'assistant'}]