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': 'Pit latrine has depth of----feet – \nSelect and explain. \nA. 2–4, B. 4–6, C. 10-Jun, D. 10–12', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]