You are presented with the question "What causes damage to the lungs?" and the following answer choices: 
- breathing
 - tar
 - HPV
 - fire
 - CFCs
 - sunshine
 - coal
 - mist

Now knowing that smoking causes direct damage to the lungs and smoke from cigarettes contains tar, which sticks to the cilia in our lungs, choose the best answer.


 

  tar       