This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
In RBC development, Haemoglobin first appears in 
Select and explain. 
A. Basophilic erythroblast, B. Polychromatic erythroblast, C. Orthochromatic erythroblast, D. Reticulocyte
B: Polychromatic erythroblast
Answer: B: Polychromatic erythroblast 
Explanation: Polychromatic/ Intermediate erythroblast is the stage where haemoglobin first appears in RBC development.