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': 'Which of the following is dental formula of a 9 year\nold child: \nSelect and explain. \nA. 6EDC21/6EDC21, B. 6EDCBA/6EDC21, C. EDC21/EDC21, D. 76EDC21/76EDC21', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]