This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Environment and health, Subject name: Social & Preventive Medicine
[{'content': 'Among the following, which one is not a major contributor to acid rains- \nSelect and explain. \nA. Carbon dioxide, B. Carbon monoxide, C. Nitric oxide, D. Sulphur dioxide', 'role': 'user'}, {'content': "Answer: B \nExplanation: Park's textbook of preventive and social medicine 23rd edition. * Rain water pick up suspended impurities and gases such as CO2, N2,O2 and ammonia,. Gaseous sulphur and nitrogen oxides are emitted from powerplants. These gases react with atmospheric water,forming dilute solution of sulphuric and nitric acid.this cause acid rain.", 'role': 'assistant'}]