This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S., Subject name: Pediatrics
[{'content': 'First cell of RBC development: \nSelect and explain. \nA. Proerythroblast, B. Intermediate normoblast, C. Reticulocyte, D. Basophilic erythroblast', 'role': 'user'}, {'content': "Answer: A \nExplanation: a. Proerythroblast(Ref: Nelson's 20/e p 2304-2308, Ghai 8/e p 330)Stage of RBC development are: Proerythroblast - Basophillic - polychromatic - Orthochromatic erythroblast - Nucleated RBC - Reticulocyte - Mature RBC.", 'role': 'assistant'}]