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': 'The following statements are, true for bleaching powder, except – \nSelect and explain. \nA. Its action is slow and long acting, B. A fresh sample contains 33% of available chlorine, C. A strenghth of 1.3% will kill most organisms, D. It is used for disinfection of faeces', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]