This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thyroid, Subject name: Surgery
Thyroid nodule of 4 cm size, mobile but causing compressive symptoms. All are true except: 
Select and explain. 
A. FNAC is investigation of choice, B. FNAC cannot distinguish follicular adenoma from carcinoma, C. Managed by total thyroidectomy, D. Cold nodule are diagnostic of malignancy
D: Cold nodule are diagnostic of malignancy
Answer: D: Cold nodule are diagnostic of malignancy 
Explanation: Thyroid nodule investigation of choice is FNAC, but does not distinguish between Adenoma and Carcinoma. Managment is Total Thryoidectomy. Risk of malignancy for cold nodule is 17-20%