About _____ of Lung Cancers Occur in Smokers

Question

About _____ of lung cancers occur in smokers.  
A) 20 percent
B) 40 percent
C) 60 percent
D) 80 percent
E) 1000 percent

Accepted Answer

Around 80 percent of lung cancers are caused by smoking, making it the biggest risk factor for developing lung cancer. Other risk factors include exposure to radon, air pollution, occupational exposure to carcinogens, and genetic factors.