This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': 'Eruption of 1st molar permanent tooth occurs at the age of \nSelect and explain. \nA. 4-5 yrs, B. 6-7 yrs, C. 7-8 yrs, D. 8-10 yrs', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Eruption of permanent molar teeth: First molar( upper jaw) - 6-7 yrs First molar ( lower jaw) -. 6-7 yrs Second molar (upper jaw)- 12-13yrs Second molar(lower jaw)-11-13yrs Third molar(upper jaw)-17-21yrs Third molar(lower jaw)-. 17-21yrs Hence, the eruption of first molar permanent tooth is at the age of 6-7 yrs. Ref: Ghai, 9th edition- Pg-11.', 'role': 'assistant'}]