COPD, or Chronic Obstructive Pulmonary Disease, is best defined as:

A. A disorder characterized by the sudden onset of bronchospasm and wheezing: Describes acute bronchospasm or asthma exacerbation rather than the chronic, largely irreversible airflow limitation of COPD. B. A chronic inflammatory lung disease characterized by airflow limitation that is not fully reversible and includes conditions such as chronic bronchitis and emphysema. It is typically associated with a history of smoking or exposure to harmful particles or gases: This describes COPD (chronic, progressive, linked to smoking/particle exposure). C. An acute respiratory illness caused by bacterial or viral infections: Describes pneumonia or bronchitis of infectious etiology rather than chronic obstructive disease. D. A condition primarily caused by allergic reactions to environmental triggers: Fits allergic asthma more than COPD, which is usually smoking- or exposure-related.