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: Anatomy
[{'content': 'Parotid duct opens - \nSelect and explain. \nA. Opposite 1st molar, B. Opposite 2nd molar, C. Into the papilla, D. Opposite incisor', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Parotid duct opens opposite the 2nd upper molor tooth.', 'role': 'assistant'}]