This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
[{'content': 'Water sample which is likely to contain chlorine. will affect the results of bacteriological analysis of water. %Mich one of the following, if added in small amount in the test tube w ill help overcome it ? \nSelect and explain. \nA. Potassium nitrate, B. Copper sulphate, C. Calcium hydrochloride, D. Sodium thiosulphate', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Sodium thiosulphate", 'role': 'assistant'}]