You are presented with the question "What damages air sacs?" and the following answer choices: 
- burning
 - coal
 - Oxygen delivered through cannulas
 - Smoking
 - Drinking alcohol
 - influenza
 - bacteria
 - Cardiovascular exercises

Now knowing that smoking causes direct damage to the lungs and smoking causes irreversible lung damage by breaking the air sacs within the lungs, choose the best answer.


 

    Smoking     