This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Flow Volume curve, Spirometry and DLCO, Subject name: Medicine
[{'content': 'A patient presents with breathlessness. He has bilateral basal crepitations, lung function tests reveal a decrease in total lung capacity (TLC) and vital capacity (VC) with normal FEV1 /FVC ratio. What is the most likely diagnosis? \nSelect and explain. \nA. Chronic bronchitis, B. Idiopathic pulmonary fibrosis, C. Cystic fibrosis, D. Allergic bronchopulmonary aspergillosis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The presence of reduced TLC & VC points to Restrictive pattern and is confirmed by normal FEV1/FVC ratio. Cystic fibrosis & Chronic Bronchitis leads to Obstructive airway disease. ABPA causes central bronchiectasis and is a suppurative lung disease.', 'role': 'assistant'}]