Lung cancer is most often caused by exposure to tobacco smoke, and lung cancer is the Godzilla of cancers. Given these facts, the godzilla of cancers is most often caused by exposure to what among the following options:
- rays or beams
 - fossil fuels
 - Pollution
 - tobacco smoke
 - light energy
 - Chemical energy
 - high temperature
 - harmful substances


 

    tobacco smoke     