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 modified class III preparation uses a dovetail on the lingual side in: \nSelect and explain. \nA. Maxillary canine, B. Mandibular canine, C. Mandibular central incisor, D. Mandibular lateral incisor', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Lingual dovetail is required for large preparations in maxillary canines.\xa0\nIt is prepared only after completion of proximal portion, because otherwise tooth structure needed for isthmus between proximal portion and dovetail might be removed when the proximal outline form is prepared.\n\nNisha Garg, Amit Garg. Textbook of Operative Dentistry.\xa0 Edition 3. Page:337', 'role': 'assistant'}]