This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Air, Light, Sound, Housing, Radiation, Waste Disposal, Subject name: Social & Preventive Medicine
[{'content': "All are criteria for 'Problem Village' EXCEPT \nSelect and explain. \nA. Radial distance > 1.6 kms, B. Depth > 50 m, C. Elevation > 100 m, D. Excess of Salt", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Problem village Radial distance - > 1.6 km Depth - >15 mtr. Elevation - > 100 mtr Excess of iron & salt, Arsenic, Fluoride', 'role': 'assistant'}]