Following are true about COPD, except: (A) Reduced FEV1, (B) Increased Residual Volume, (C) Decreased Diffusion capacity (DLco), (D) Decreased Maximal Expiratory Flow Rate (MEFR)
Answer is C. COPD is an obstructive lung disease. Obstructive diseases have reduced FEV1, FVC and reduced FEV1/FVC. Flow rates like MEFR (Maximal Expiratory Flow Rate ) are also reduced. 
Due to air-trapping, the residual volume is increased. 
Reduction in DLco is seen interstitial lung diseases or pneumonias, not in COPD . 
DLco may be reduced in Emphysema due to alveolar damage.