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
[{'content': 'Iron stores are best indicated by \nSelect and explain. \nA. Serum ferritin, B. Serum iron, C. Serum transferrin, D. TIBC', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Serum ferritin reflects the storage of iron which is decreased in Iron deficiency anaemia.\nIt is the most sensitive marker.', 'role': 'assistant'}]