This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiology, Subject name: Social & Preventive Medicine
[{'content': 'All of the following are false about bleaching powder except- \nSelect and explain. \nA. Contains 20% available chlorine, B. 20% solution used for disinfection of faces, C. Unstable compound on storage, D. Not used for disinfection of faces & urine', 'role': 'user'}, {'content': "Answer: D \nExplanation: Chlorinated lime Contains about 33 percent of the available chlorine Used in the strength of 1 to 3 percent Bleaching powder is widely used in public health practice in India for disinfection of water, feces, and urine Ref: 25th edition, Park's Textbook of Preventive and Social Medicine, Page no. 141", 'role': 'assistant'}]