This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hematology, Subject name: Pediatrics
[{'content': 'Which organ is the primary site of hematopoiesis in the fetus before midpregnancy \nSelect and explain. \nA. Bone, B. Liver, C. Spleen, D. Lung', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Primary site of gematopoesis in fetus before mid pregnancy is liver. Reference : Ghai essential of pediatrics, eighth edition, p.no:330', 'role': 'assistant'}]