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 region is involved in plummer-vinson syndrome- \nSelect and explain. \nA. Pyriform sinus, B. Post cricoid region, C. Valleculae, D. Posterior pharyngeal wall', 'role': 'user'}, {'content': 'Answer: B \nExplanation: It is associated with an oesophagal web in post cricoid region and 10% patients develops post cricoid carcinoma.', 'role': 'assistant'}]