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': 'The valuable test for evaluating caries activity in very\nyoung children is \nSelect and explain. \nA. Lactobacillus colony count test, B. Swab test, C. Alban test, D. Calorimetric snyder test', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]