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': 'True about Ruffle stage of ameloblast is \nSelect and explain. \nA. Proximal junction is loose, B. Active uptake of Calcium, C. Separate tomes process from cell proper, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]