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 20 year old girl, presents with 9 month history of neck swelling with thyrotoxic  symptoms.  On investigation, increased T4 and decreased TSH with palpable 2 cm nodule was found. Next investigation will be: 
Select and explain. 
A. USG, B. Thyroid scan, C. Radioactive iodine uptake, D. CT scan
B: Thyroid scan
Answer: B: Thyroid scan 
Explanation: None