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': 'Stellate Reticulum First appears in: \nSelect and explain. \nA. Advanced Bell Stage., B. Early Bell Stage., C. Bus Stage., D. Cap Stage.', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]