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': 'During examination of parotid gland, parotid duct can be palpated at the following except: \nSelect and explain. \nA. Anterior border of masseter, B. At the opening just opposite to lower second molar, C. Pierced to the buccinator, D. At the anterior border of parotid gland', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Parotid Duct (Stenson’s Duct)\nParotid duct, about 5 cm long, emerges from the middle of the anterior border of the gland and opens into the vestibule of the mouth opposite the crown of upper second molar tooth.', 'role': 'assistant'}]