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: Biochemistry
[{'content': 'Transport form of iron is \nSelect and explain. \nA. Transferrin, B. Ferritin, C. Apoferritin, D. Lactoferrin', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]