A proven consequence of smoking is lung cancer. Thus, option B is correct.
Lung cancer is one of the most aggressive cancers in the world, and is also the cancer that kills the most people in America every year
Emphysema is a chronic pulmonary disease that occurs when the air sacs in the lungs, called alveoli, enlarge and get damaged.
This condition is mostly caused by smoking, and makes up a very significant risk factor for lung cancer.
Thus, option B is correct is lung cancer.
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