Fact 1: Smoking causes direct damage to the lungs.

Fact 2: Smoke from cigarettes contains tar, which sticks to the cilia in our lungs.

Given the two facts above, answer the question "What causes damage to the lungs?" with the following options: 
- breathing
 - tar
 - HPV
 - fire
 - CFCs
 - sunshine
 - coal
 - mist


 

  tar       