This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Pharmacology
[{'content': 'The difference between iron sorbitol-citric acid and iron dextran is that the former \nSelect and explain. \nA. Cannot be injected i.v., B. Is not bound to transferrin in plasma, C. Is not excreted in urine, D. Produces fewer side effects', 'role': 'user'}, {'content': 'Answer: A \nExplanation: (Ref: KDT 6/e p586) Iron sorbitol citrate should not be used i.v. because it may rapidly saturate the transferrin receptors and can result in high concentrations of free iron.', 'role': 'assistant'}]