This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Emphysema pathologically involves beyond the- 
Select and explain. 
A. Bronchi, B. Terminal bronchiole, C. Respiratory bronchiole, D. Alveolar Sac
B: Terminal bronchiole
Answer: B: Terminal bronchiole 
Explanation: Emphysema

Emphysema is a condition of the lung characterized by abnormal permanent enlargement of the airspaces distal to the terminal bronchioles, accompanied by destruction of their walls and without obvious fibrosis.
"Destruction of walls" is necessary to define emphysema. Enlargement of airspaces without destruction of their walls is termed overinflation, for example, the distention of airspaces that occurs in the remaining lung after unilateral pneumonectomy.