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: Pharmacology
[{'content': 'Thyroid gland function is best monitored by which of the following: \nSelect and explain. \nA. Basal metabolic rate (BMR), B. Thyroxine and tri–iodothyronine uptake, C. Level of thyroid stimulating hormone, D. Level of protein bound iodine', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]