**Core Concept**
COPD (Chronic Obstructive Pulmonary Disease) is characterized by a progressive decline in lung function, primarily due to airflow limitation caused by chronic inflammation and destruction of lung tissue. This leads to symptoms such as shortness of breath, wheezing, and a cough.

**Why the Correct Answer is Right**
The correct answer is related to the pathophysiology of COPD, which involves the breakdown of lung tissue and airway remodeling. In COPD, there is an abnormal increase in the size and number of goblet cells in the airway epithelium, leading to an excessive mucus production and impaired mucociliary clearance. This results in the characteristic cough and sputum production seen in COPD patients.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not directly related to the pathophysiology of COPD. While it is true that COPD patients often have a history of smoking, this option is too vague and does not specifically address the underlying mechanisms of the disease.
* **Option B:** This option is incorrect because it describes a feature of asthma, not COPD. Asthma is characterized by airway inflammation, hyperresponsiveness, and reversible airflow obstruction, which is distinct from the chronic, progressive nature of COPD.
* **Option C:** This option is not accurate because it describes a feature of pulmonary fibrosis, a different lung disease characterized by scarring and thickening of lung tissue.

**Clinical Pearl / High-Yield Fact**
One key feature of COPD is the presence of **airway remodeling**, which involves the thickening of the airway wall and the formation of new tissue, leading to a permanent loss of lung function.

**Correct Answer: B. Increased number of goblet cells in the airway epithelium.**