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': 'Properties of Ideal disinfectant except \nSelect and explain. \nA. Insoluble in water, B. Non toxic, C. Fast acting, D. Residual effect', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]