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: Surgery
Risk of malignancy in cold nodule of thyroid is 
Select and explain. 
A. 0.10%, B. 2%, C. 20%, D. 30%
C: 20%
Answer: C: 20% 
Explanation: Risk of malignancy in hot nodule is 4%.
Risk of malignancy in cold nodule is 20%.