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: Surgery
[{'content': 'Plasma of hyperthyroid patient contains excess of: \nSelect and explain. \nA. T3., B. Free thyroxine., C. Protein bound thyroxine., D. RT3.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]