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': 'True about plummer vinson syndrome: \nSelect and explain. \nA. Web is M/C in lower esophagus, B. Web is M/C in Mid esophagus, C. Web is M/C in postcricoid region, D. It occurs due to abnormal vessels', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Plummer-Vinson syndrome patients present with dysphagia due to web in the postcricoid region and due to incoordinated swallowing secondary to esophageal spasm', 'role': 'assistant'}]