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: Pharmacology
[{'content': 'Fastest acting Antithyroid medication is: \nSelect and explain. \nA. Pottasium iodide, B. Propylthiouracil, C. Carbimazole, D. Methamizole', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Pottasium iodide', 'role': 'assistant'}]