Answer:
Option (d).
Step-by-step explanation:
Chronic bronchitis may be defined as the medical condition in which the cough persists with mucus in the lungs for more than a month. This may occur due to smoking or inhaling of dust or smoke.
The chronic bronchitis makes the bronchial mucosa thick and mixes with the cough. This hinders the breathing in the individual that suffers from the chronic bronchitis. The individual may have painful coughing and shows wheeziness, shortness of breath.
Thus, the correct answer is option (d).