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
Hemoglobin begins to appear by which stage of erythropoiesis? 
Select and explain. 
A. Proerythroblast, B. Early normoblast, C. Intermediate normoblast, D. Late normoblast
C: Intermediate normoblast
Answer: C: Intermediate normoblast 
Explanation: Though the earliest evidence of Hb synthesis appears to be in early normoblast, Hb begins to appear in detectable amounts by intermediate normoblast.