This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neck Triangles and parotid gland, Subject name: Anatomy
Parotid duct opens at the level of? 
Select and explain. 
A. First mandibular molar, B. Second mandibular molar, C. First maxillary pre molar, D. Second maxillary molar
D: Second maxillary molar
Answer: D: Second maxillary molar 
Explanation: Parotid duct/Stenson's duct passes through the buccinator muscle and pierces buccal fat, opening into the vestibule of the mouth at the parotid papilla, which lies opposite to the 2nd maxillary (upper) molar tooth.