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': 'A child has the permanent molar and 3 deciduous molars filled with amalgam. 2 other deciduous teeth were cariously decayed, 2 deciduous upper incisors are missing. The decayed and filled score of child is: \nSelect and explain. \nA. 3, B. 5, C. 7, D. 8', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]