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: Dental
[{'content': 'Not safe disposal but good for soil building: \nSelect and explain. \nA. Incineration, B. Controlled tipping, C. Composting, D. Dumping', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]