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': 'Disinfecting action of chlorine is due to? \nSelect and explain. \nA. Hypochlorous acid, B. Hypochlorine ion, C. Hydrochloric acid, D. Both Hypochlorous acid and Hypochlorite ion', 'role': 'user'}, {'content': "Answer: D \nExplanation: Chlorination: It is a method of water purification. When chlorine is added to water there is a formation of hydrochloric and hypochlorous acids. The hydrochloric acid is neutralized by the alkalinity of water. The hypochlorous acid ionizes to form hydrogen ions and hypochlorite ions. The disinfecting action of chlorine is due to hypochlorous acid and to a small extent due to hypochlorite ion. Park's textbook of preventive and social medicine.K Park. Edition 23.Pg no: 714", 'role': 'assistant'}]