A Patient Who Has Chronic Obstructive Pulmonary Disease from Having

A patient who has chronic obstructive pulmonary disease from having been a smoker for a number of years is tested for lung volume.It is determined that the patient's tidal volume is 0.6 liters, his inspiratory reserve volume is 2.6 liters, his expiratory reserve volume is 1 liter, and his residual volume is 3.2 liters.Prior to smoking, this man's tidal volume was 0.5 liters, his inspiratory reserve volume was 3.1 liters, his expiratory reserve volume was 1.2 liters and his residual volume was 1.2 liters.These numbers indicate that

A) the vital capacity of this patient has not been altered.
B) the vital capacity of this patient has increased since he started smoking.
C) the total lung volume of this patient is 50% less than when he started smoking.
D) the increased total lung volume of this patient improves his ability to extract oxygen from the air he breathes.
E) the increased residual volume of this patient decreases the patient's respiratory ability.