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': 'First to be developed is - \nSelect and explain. \nA. Neural pit, B. Neural groove, C. Neural fold, D. Primitive streak', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]