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': 'Smooth surface caries is characterized by spread of caries in enamel and dentin as cones. These alignment in enamel and dentin is \nSelect and explain. \nA. Base to base, B. Apex to base, C. Apex to apex, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]