Which term refers to pneumonia, an infection of the lung?

• A. Pertussis
• B. Pneumothorax
• C. Croup
• D. Pneumonia

Answer: (D)

Pneumonia denotes an infection of the lung parenchyma. It involves inflammation and often consolidation of the lung tissue due to pathogens, which is why the term itself is used for this condition. The other terms describe different respiratory issues: Pertussis is whooping cough caused by Bordetella pertussis, pneumothorax is air in the pleural space causing lung collapse, and croup is an inflammatory condition of the upper airway that produces a characteristic barking cough. So the term that specifically refers to an infection of the lung is pneumonia.