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: Medicine
[{'content': 'What does Serum ferritin level \nSelect and explain. \nA. Decreased capacity to absorb iron, B. Microcytic hypochromic anemia, C. Absent body iron stores, D. Sideroblastic anemia', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The serum ferritin level is the laboratory test to estimate iron stores. As iron stores are depleted, the serum ferritin falls to Reference: Harrisons Principles of Internal Medicine, 18th Edition, Page 847', 'role': 'assistant'}]