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': 'Nutrition for ameloblasts after 1st layer of enamel is laid is \nSelect and explain. \nA. Dental sac, B. Odontoblastic process, C. REE, D. Dental papilla', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]