This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S., Subject name: Pediatrics
[{'content': 'Which of the following is the major site of erythropoietin production during the fetal stage: \nSelect and explain. \nA. Liver, B. Yolk, C. Bone, D. Spleen', 'role': 'user'}, {'content': "Answer: A \nExplanation: a. Liver(Ref: Nelson's 20/e p 2306)Erythropoietin (EPO) is produced in fetal liver during 1st & 2nd trimesters, by cells of monocyte/macrophage origin.After birth, the anatomic site of EPO production shifts to the kidney.", 'role': 'assistant'}]