This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: RBC Development and Classification of Anemias, Subject name: Pathology
1st stage of RBC development is? 
Select and explain. 
A. Erythroblast, B. Intermediate normoblast, C. Late normoblast, D. Reticulocyte
A: Erythroblast
Answer: A: Erythroblast 
Explanation: Stages of RBC development: Proerythroblast - Early normoblast (Basophilic erythroblast) - Intermediate normoblast (Polychromatophilic erythroblast) - Late normoblast (Ohochromatic erythroblast) - Reticulocyte - Mature red cell EXTRA EDGE: - Hb can be 1st detected in proerythroblast - only by electron microscope - Hb can be 1st detected by routine staining in Intermediate Normoblast - 1st Non-nucleated cell seen in RBC development - Reticulocyte