This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thorax, Subject name: Anatomy
Smallest functional unit of the lung is 
Select and explain. 
A. Acinus, B. Alveolus, C. Lobules, D. Broncho pulmonary segments
C: Lobules
Answer: C: Lobules 
Explanation: [Cl (Lobule) (219 - I.B.Singh 5th)Lobule - small segment, is the functional unit of the lung including respiratory bronchioles, alveolar ducts and sacs and alveoli