This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pituitary-Hypothalmic System and Thyroid, Subject name: Pharmacology
[{'content': 'Fastest acting anti-thyroid drug is \nSelect and explain. \nA. Sodium Iodide, B. Propyl thiouracil, C. Methimazole, D. Thiocyanate', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Secretion inhibitors:These are fastest acting anti thyroid drugs. NaI KI Lugol iodine Thyroid peroxidase inhibitor Carbimazole/Methimazole Propylthiouracil Thiocyanate is Na+I+sympoer (NIS) inhibitor. Highly toxic Not used clinically', 'role': 'assistant'}]