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': 'Thinnest labial plate is found in the region of: \nSelect and explain. \nA. Upper central incisors, B. Lower central incisors, C. Upper canines, D. Lower canines', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]