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
Investigation of choice in discrete thyroid swelling is- 
Select and explain. 
A. Isotope scans, B. Ultrasonography, C. Autoantibody titers, D. FNAC
D: FNAC
Answer: D: FNAC 
Explanation: None