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': 'Enamel colour of Primary and permanent teeth respectively are \nSelect and explain. \nA. China white and Ivory white, B. Ivory white and yellowish white, C. Grey white and China white, D. All of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]