A 54-year-old man with a pack-a-day history of smoking complains to you of a chronic cough. The cough has lingered for greater than four months this year, and he reports a similar episode last year....

A 54-year-old man with a pack-a-day history of smoking complains to you of a chronic cough. The cough has lingered for greater than four months this year, and he reports a similar episode last year. On exam, he appears cyanotic, in particular at the tips of his fingers, which are also club shaped, indicating chronic hypoxia. His FEV1 is markedly decreased, while his FVC remains near normal. What is your diagnosis?

A. Asthma

B. Chronic bronchitis

C. Bronchogenic carcinoma

D. Emphysema