This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Medicine
[{'content': 'Most reliable marker for hypothyroidism: \nSelect and explain. \nA. T3, B. T4, C. TSH, D. Thyroxine binding globulin', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. (c) TSHRef : Harrison 19th ed. 12289* Best test for diagnosis of hypothyroidism is T.S.H (Thyroid Stimulating Hormone).* TSH can also be used for monitoring response to treatment.', 'role': 'assistant'}]