This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology and breast, Subject name: Surgery
A 20 yr old girl presents with 9 month history of neck swelling with thyrotoxicosis 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: In clinical cases of thyroid nodule, Thyroid profile (T3 T4 TSH) is done. If TSH is low, thyroid scan is done to see if nodule is hot or cold. If TSH is low or normal, ultrasound followed by FNAC is done Source :Sabiston 20 th edition Pg 890