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
[{'content': 'Which is the investigation of choice to differentiate between benign and malignant thyroid nodule? \nSelect and explain. \nA. USG, B. FNAC, C. Scintigraphy, D. Biopsy', 'role': 'user'}, {'content': 'Answer: D \nExplanation: FNAC is investigation of choice to diagnose solitary thyroid nodule but it cannot differentiate follicular adenoma from follicular carcinoma Diagnosis of follicular carcinoma is based on vascular invasion/ capsular invasionthat can be seen on biopsy only and not on FNAC', 'role': 'assistant'}]