Which of the following is a common cause of obstructive lung disease?

Chronic obstructive pulmonary disease (COPD) is a common cause of obstructive lung disease because it encompasses a range of conditions, primarily emphysema and chronic bronchitis, that lead to airflow limitation. This limitation is not fully reversible and is attributed to the inflammatory response of the lungs to harmful particles or gases, often due to smoking or environmental factors.

In COPD, changes in the lung structure, including the destruction of alveoli and chronic inflammation of the airways, cause narrowing and obstruction, making it difficult for air to flow in and out of the lungs. Patients often experience symptoms such as breathlessness, wheezing, and a chronic cough, all of which highlight the obstructive nature of the disease.

The other options, while they may affect respiratory function, do not primarily lead to obstructive lung disease. For example, interstitial lung disease typically leads to restrictive lung patterns due to scarring and inflammation in the lung interstitium. Sarcoidosis can cause a myriad of respiratory symptoms and may lead to restrictive lung disease or granuloma formation, but it does not predominantly cause the airflow obstruction seen in COPD. Scoliosis can impact lung function by limiting lung expansion due to lung volume reduction, but it is more often classified as