The correct option is
A a, c, d only
(a) Coronary Artery Disease(CAD): Also called atherosclerosis, affects the vessels that supply blood to the heart muscles. It is caused by deposits of calcium, fat, cholesterol and fibrous tissues which makes the lumen of arteries narrower. Cigarette smoking and alcohol consumption can be an important cause of CAD.
(b) Gastric ulcer: It is kind of peptic ulcer that occurs inside the stomach when acid in the digestive tract eats away all the inner surface of the stomach or small intestine and creates a painful open sore that may bleed.
(c) Emphysema: In this disorder, the alveolar walls are damaged due to which the respiratory surface is decreased. A major cause of this is cigarette smoking.
(d) Lung cancer: It is the type of cancer that begins in the lungs and most often occurs in the people who smoke.
(e) Hypoxia: A condition in which the body or a part of the body is deprived of adequate oxygen supply at the tissue level.
(f) Bronchitis: It is the inflammation of the bronchi.
So, the correct option is 'a.c.d only'.