This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hematology, Subject name: Pediatrics
[{'content': 'First change of improvement noted after iron therapy is initiated \nSelect and explain. \nA. Decreased irritability, B. Reticulcytosis, C. Increase in serum iron levels, D. Replenishment of iron stores', 'role': 'user'}, {'content': 'Answer: A \nExplanation: First change of improvement noted after iron therapy is decreased irritability followed by increased reticulocyte count. Reference: GHAI Essential pediatrics, 8th edition', 'role': 'assistant'}]