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: Medicine
[{'content': 'The best marker for thyroid related disorder is: \nSelect and explain. \nA. T3, B. T4, C. TSH, D. Thyroglobulin', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Answer is C (TSH): TSH is the most useful marker for Thyroid Related Disorders. With rare exceptions a normal TSH level excludes a primary abnormality of thyroid function. The enhanced sensitivity and specificity of TSH assays have greatly improved laboratory assessment of thyroid function', 'role': 'assistant'}]