This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thyroid Gland, Subject name: Surgery
[{'content': 'Wolf Chaikoff effect is due to excess \nSelect and explain. \nA. Iodide, B. Radio iodine, C. Propylthiouraci, D. Thyroxine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) IodidesRef: Schwartz 9th Edition Page2599/E book* Excessively large doses of iodide may lead to initial increased organification, followed by suppression, a phenomenon called the Wolff-Chaikoff effect', 'role': 'assistant'}]