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: ENT
[{'content': 'Which of the following part is NOT included in hypopharynx - \nSelect and explain. \nA. Pyriform sinus, B. Postcricoid region, C. Anterior pharyngeal wall, D. Posterior pharyngeal wall', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Clinically, hypopharynx is subdivided into three regions:-\n\n\nThe pyriform sinus\nPost-cricoid region\nThe posterior pharyngeal wall', 'role': 'assistant'}]