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': 'The orthodontic diagnosis focuses on \nSelect and explain. \nA. Full smile, B. Emotional smile, C. Social smile, D. Gummy smile only', 'role': 'user'}, {'content': 'Answer: C \nExplanation: There are two types of smiles: the posed or social smile, and the emotional smile.\xa0\nThe social smile is reproducible, and is the one that is presented to the world routinely.\xa0\nThe emotional smile varies with the emotion being displayed.\xa0\nThe social smile is the focus of orthodontic diagnosis.\nContemporary orthodontics, Proffit, 4th edition page 186', 'role': 'assistant'}]