True about the chronic obstructive pulmonary disease (COPD): (A) FEVI <30 of predicted value, (B) FEV1/FVC<0.7, (C) total lung capacity increased, (D) All
Answer is D. In COPD, airflow obstruction is demonstrated by spirometry in which the post-bronchodilator FEV1/FVC is less than 70%. 
The severity of COPD may be defined in relation to the post-bronchodilator FEV1 which is <30% predicted in very severe type. 
Measurement of lung volumes provides an assessment of hyperinflation.COPD is characterised by an increase in residual volume, residual volume/total lung capacity ratio, and progressive hyperinflation(increased total lung capacity) late in the disease.