This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Blood, Subject name: Pediatrics
[{'content': 'The earliest indicator of response after starting iron therapy in a 6 year old with iron deficiency is: \nSelect and explain. \nA. Increased ferritin, B. Increased haemoglobin, C. Increased reticulocyte count, D. Increased serum iron', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C. Increased reticulocyte count* Reticulocyte count is the earliest to rise after starting iron therapy.* This is followed by elevation of haemoglobin levels.* Body iron stores are repleted after the correction of haemoglobin levels.', 'role': 'assistant'}]