This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2018, Subject name: Surgery
[{'content': 'Malignancy in a multinodular goiter is most often:- \nSelect and explain. \nA. Follicular carcinoma, B. Papillary carcinoma, C. Anaplastic carcinoma, D. Medullary carcinoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Follicular ca: - Seen in iodine deficient areas - M/C malignancy in long standing goiter - M/c malignancy in multinodular goiter Papillary ca: - Seen in iodine sufficient areas - M/C thyroid malignancy Anaplastic ca: - Rare; m/c seen in females - Usually seen in 7th - 8th decade of life Medullary ca: - Arise from Parafollicular C cells - C cells derived from ultimobranchial bodies', 'role': 'assistant'}]