All the following are true about Chronic Obstructive lung disease except:

Answer is D (Decreased diffusing capacity) : Diffusion capacity is not affected in Obstructive lung diseases 9(acute or chronic). It is decreased in restrictive lung disease. Decreased in expiratory flow rate is a hallmark of obstructive lung disease. (i,MEFR) Residual volume is increased & FEVI/FVC is decreased (FEV1 is also decreased). FEV1=forced expiratory volume in one second; FVC=Forced Vital Capacity; FEF25_75=Forced Expiratory Flow at 25%=75% vital capacity; TLC= Total Lung Capacity; DLCO=Diffusion Capacity of the Lung for Carbon monoxide.