This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Growth and development, Subject name: Pediatrics
[{'content': 'Which of the following is true about Eruption of teeth __________ \nSelect and explain. \nA. Premolar appear in Primary dentition, B. Incisors appear first in secondary dentition, C. 3rd molar is last to develop, D. Hypothyroidism delays dentition', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Eruption times vary from child to child.The first teeth begin to break through the gums at about 6 months of age. Usually, the first two teeth to eruptare the two bottom central incisors (the two bottom front teeth). Next, the top four front teeth emerge. Reference: GHAI Essential pediatrics, 8th edition', 'role': 'assistant'}]