Which of the following is not true about lung cancer?

Q. Which of the following is not true about lung cancer?

A.            N-nitrosamines and polycyclic aromatic hydrocarbons (PAHs) are primarily responsible for lung cancer development

B.            Lung cancer have some familial preponderance studies showing odds ration ranging from 1.63 to 3.6

C.            25% of worldwide lung cancer cases are least in part related to occupational exposures

D.            COPD and pulmonary fibrosis are risk factors for lung cancer, independent of smoking

Answer: 25% of worldwide lung cancer cases are at least in part related to occupational exposures.