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': 'Nutritional supply of the ameloblasts during most of their life cycle is from the: \nSelect and explain. \nA. Dental pulp, B. Odontoblastic processes, C. Dental sac, D. Reduced dental organ', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Before the appearance of 1st layer of dentin, ameloblast derive nutrition from dental papilla. After dentin layer formation they receive nutrition from the capillaries of dental sac that surround the outer enamel epithelium.', 'role': 'assistant'}]