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
Most reliable marker for hypothyroidism: 
Select and explain. 
A. T3, B. T4, C. TSH, D. Thyroxine binding globulin
C: TSH
Answer: C: TSH 
Explanation: 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.