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
A patient diagnosed with papillary carcinoma of thyroid underwent whole body iodine scan 6 weeks after surgery, which revealed residual disease. Next best step is : 
Select and explain. 
A. Surgical removal of residual disease, B. User neck + Serum thyroglobulin level, check for, C. Radioiodine ablation, D. FNAC of the residual tissue F/B radioiodine ablation
C: Radioiodine ablation
Answer: C: Radioiodine ablation 
Explanation: Post operative follow up protocol.