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
Treatment of choice for medullary carcinoma: 
Select and explain. 
A. Thyroxin therapy., B. Radioiodine., C. External radiation, D. Total Thyroidectomy.
D: Total Thyroidectomy.
Answer: D: Total Thyroidectomy. 
Explanation: None