This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Integrated QBank, Subject name: Unknown
[{'content': 'A 65-year-old male presented to the OPD with progressive dyspnea on exeion for 3 months. Patient records told that he had an episode of necrotizing pancreatitis along with ARDS in the past for which he was mechanically ventilated for a long time. Patient is a chronic smoker. On examination, low pitched inspiratory and expiratory wheeze is heard over mid-chest area. PFTs revealed, FEV1 is 78% of predicted. FEV1/FVC ratio is 60%. Flow volume curve is given. What is the most likely diagnosis in the above case: - \nSelect and explain. \nA. COPD, B. Subglottic stenosis, C. Idiopathic pulmonary fibrosis, D. Unilateral vocal cord paralysis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Subacute dyspnea, stridor and airway obstruction - consistent with diagnosis of subglottic stenosis - related to his prior prolonged mechanical ventilation. Flow volume curve loop is suggestive of fixed airflow obstruction.', 'role': 'assistant'}]