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: Anatomy
[{'content': 'Central nervous system develops from ? \nSelect and explain. \nA. Ectoderm, B. Endoderm, C. Mesoderm, D. All three germ layers', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Nervous system develops from ectoderm (neuroectoderm).', 'role': 'assistant'}]