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: Physiology
[{'content': 'Not a site of hematpoiesis in fetus ? \nSelect and explain. \nA. Kidney, B. Liver, C. Spleen, D. Yolk sac', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Kidney", 'role': 'assistant'}]