This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Blood: RBCs, Anemia, and Polycythemia, 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 Erythropoies siteso Intrauteriney 0-10 weeksy 10 weeks - 5 monthsy 5 month onward-Yolk sac-Liver (maj or organ) and spleen- Bone marrowo After birthUpto 20 years - Bone marrow of all bonesAfter 20 years - Flat bones of axial skeletal and proximal end of humerus and femur.", 'role': 'assistant'}]