This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Blood Physiology, Subject name: Physiology
[{'content': 'Hemoglobin begins to appear by which stage of erythropoiesis? \nSelect and explain. \nA. Proerythroblast, B. Early normoblast, C. Intermediate normoblast, D. Late normoblast', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Though the earliest evidence of Hb synthesis appears to be in early normoblast, Hb begins to appear in detectable amounts by intermediate normoblast.', 'role': 'assistant'}]