A 52-year-old woman from a region with longstanding dietary iodine deficiency presents with a solitary thyroid nodule. Vital signs are stable (BP 128/82, HR 78, RR 16, Temp 37°C). TSH is elevated at 8.2 mIU/L. Fine-needle aspiration biopsy shows follicular cells without atypia. Thyroid ultrasound reveals no lymphadenopathy. Definitive diagnosis requires demonstration of capsular invasion on histopathology. Which of the following is the most likely diagnosis?

1. A)Follicular thyroid carcinomaGABARITO
2. B)Medullary thyroid carcinoma
3. C)Subacute thyroiditis
4. D)Thyroid lymphoma
5. E)Papillary thyroid carcinoma