Each of these answers could, in fact, be correct. However, when looking at statistics and probabilities, smoking is likely the cause of the cancer. While lung cancer does occur in non-smokers, it is much more probable to take place in someone that has a history of smoking.
Inhalation of hazardous chemicals and particles like silica and asbestos absolutely increase the chances of cancer. Unfortunately, smoking is the leading cause of lung cancer with 90% of cases being linked to it. Similarly, passive smoking/breathing secondhand smoke is harmful but not as much so as inhaling radon gas.
Smoking -(c) correct. smoking remains the most frequent cause of lung cancer. lung cancer does, however, occur in nonsmokers. a small cell anaplastic carcinoma, as in this patient, is virtually always seen in smokers.(a) incorrect. silicosis increases the risk for lung cancer slightly by about 2 fold.(b) incorrect. radon is probably the second leading cause of lung cancer. however, most cases of lung cancer in which exposure to radon gas has been identified also occur in smokers.(d) incorrect. however, asbestos exposure increases the risk for lung cancer in smokers even more.(e) incorrect. passive smoking could probably be right behind radon exposure as the second leading cause for lung cancer.
