This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Social & Preventive Medicine
[{'content': 'Liquid chemical waste is discarded in \nSelect and explain. \nA. yellow, B. red, C. black, D. blue', 'role': 'user'}, {'content': 'Answer: A \nExplanation: ref : park 21st ed', 'role': 'assistant'}]