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: Physiology
[{'content': 'TSH is normal in: September 2006 \nSelect and explain. \nA. Hypehyroid, B. Euthyroid, C. Hypothyroid, D. Graves', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B: EuthyroidIn hypehyroidism:Total plasma T3, T4, 3 is highFree plasma T3, T4, 3 is highPlasma TSH is lowIn hypothyroidism:Total plasma T3, T4, 3 is lowFree plasma T3, T4, 3 is lowPlasma TSH is highGraves disease is most common cause of hypehyroidism.', 'role': 'assistant'}]