Questions: What is the primary cause of chronic obstructive pulmonary disease (COPD)? Genetic factors Occupational exposures Cigarette smoking Bacterial infections

The answer is the third one (C): Cigarette smoking.

Explanation for each option:

1. Genetic factors: While genetic factors can contribute to the development of COPD, they are not the primary cause. A well-known genetic factor is alpha-1 antitrypsin deficiency, but it accounts for a small percentage of COPD cases.

2. Occupational exposures: Occupational exposures to dust, chemicals, and fumes can increase the risk of developing COPD, but they are not the leading cause. These factors are more significant in certain industries and occupations.

3. Cigarette smoking: This is the primary cause of COPD. The majority of COPD cases are directly linked to long-term cigarette smoking. The harmful chemicals in cigarette smoke cause inflammation and damage to the airways and lung tissue, leading to the development of COPD.

4. Bacterial infections: While bacterial infections can exacerbate COPD symptoms and lead to acute exacerbations, they are not the primary cause of the disease. Infections can complicate the condition but are not the root cause.

Summary: The primary cause of chronic obstructive pulmonary disease (COPD) is cigarette smoking.