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 patient with long standing multinodular goitre develops hoarseness of voice; also, the swelling undergoes sudden increase in size. Likely diagnosis is 
Select and explain. 
A. Follicular ca, B. Papillary ca, C. Medullary ca, D. Anaplastic ca
A: Follicular ca
Answer: A: Follicular ca 
Explanation: Ans. is 'a' i.e., Follicular Ca History of sudden growth in a long standing goiter and hoarseness are suggestive of malignant change. Most common carcinoma to develop in developing in long standing multinodular goiter is Follicular carcinoma.