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': 'Neonatal lines are found in all of the following except: \nSelect and explain. \nA. Enamel of primary incisors, B. Enamel of permanent canines, C. Enamel and dentin of permanent first molars, D. Dentin of permanent mandibular incisors', 'role': 'user'}, {'content': 'Answer: B \nExplanation: In deciduous teeth and in permanent molars and lower incisors, in which the enamel and dentin are formed partly before and partly after birth, the prenatal and postnatal enamel and dentin, are separated by the neonatal line or ring.\nNote:\nAccording to some authors, neonatal line is not seen in permanent lower incisors.', 'role': 'assistant'}]