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': 'Habits are classified into pressure and non pressure habits  by \nSelect and explain. \nA. Morris and Bohanna, B. Kingsley, C. Klein, D. Finn', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]