This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chronic Obstructive Pulmonary Disease, Subject name: Medicine
[{'content': 'In COPD which is true - \nSelect and explain. \nA. FEV1/FVC<0.7, B. FEVl/FVC|, C. RV|, D. TLV|', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., FEV1 / FVC < 0.7 The lung function tests in obstructive lung disease can be summarized as -o Forced expiratory' vital capacity (FEVc) - Normal to slightly decreasedo Forced expiratory volume in 1 sec (FEV1)-Decrease out of proportion to FVCo FEV1/FEV1-Decrease can be as low as 20% - 30%o Peak expiratory flow rate-Decreasedo Total lung capacity-Increaseo Residual volume-Increaseso Functional residual capacity-Higher", 'role': 'assistant'}]