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: Medicine
[{'content': 'Transferrin saturation is? \nSelect and explain. \nA. Serum iron/TIBC x100, B. TIBC/serum iron x100, C. TIBC/serum iron, D. Serum iron/TIBC', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A. Serum iron / TIBC x100Transferrin saturation =TIBCSerumiron x100Usual valuesNormal reference ranges are:a. Serum iron: 60-170mg/mlb. TIBC:240-450mg/mlc. Transferrin saturation: 15-50% (males), 12-45% (females)', 'role': 'assistant'}]