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': 'Which of the following has impoant role in initiation and maintenance of primitive streak \nSelect and explain. \nA. FGF-8, B. BMP-4, C. EGRF, D. Nodal gene', 'role': 'user'}, {'content': 'Answer: D \nExplanation: D i.e. Nodal gene The primitive streak is initiated and maintained by expression of nodal, a member of transforming growth factor /3 (TGF - 13) superfamilyQ.', 'role': 'assistant'}]