單項選擇題
A 45-year-old man has smoked two packs of cigarettes per day for 20 years. For the past 4 years, he has had a chronic cough with copious mucoid sputum over 4 months every year. Which of the following
A、Bronchiectasis
B、Asthmatic bronchitis
C、Chronic bronchitis
D、Hypersensitivity pneumonitis