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: Pathology
[{'content': 'Most demineralised zone in enamel caries \nSelect and explain. \nA. Translucent zone, B. Body of lession, C. Dark zone, D. Surface zone', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]