This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Evaluation of a Thyroid Nodule, Subject name: Surgery
[{'content': 'Percentage of cold nodules that becomes malignant are? \nSelect and explain. \nA. 5%, B. 15%, C. 20%, D. 40%', 'role': 'user'}, {'content': 'Answer: C \nExplanation: ANSWER: (C) 20 %REF: Bailey and love 25th ed page 779See details of thyroid nodules in Surgery June 2011About 80% of discrete swellings are cold. The risk of malignancy is higher in "cold" lesions (20%) compared to "hot" or "warm" lesions (<5%).', 'role': 'assistant'}]