A 40-year-old woman presents with a thyroid nodule discovered on ultrasound. Vital signs are stable (BP 128/82, HR 78, RR 16, Temp 37°C). Laboratory studies reveal elevated calcitonin (285 pg/mL; normal <10) and normal TSH (1.8 mIU/L). Fine-needle aspiration biopsy demonstrates nests of malignant cells within an amyloid-rich stroma. No lymphadenopathy is noted on imaging. Which cell type gives rise to this malignancy?

1. A)Anterior pituitary thyrotrophs
2. B)Parathyroid chief cells
3. C)Follicular cells derived from endoderm
4. D)Adrenal cortical cells derived from mesoderm
5. E)Parafollicular C cells derived from neural crestGABARITO