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
[{'content': 'Commonest presenting complaints of medullary carcinoma thyroid - \nSelect and explain. \nA. Diarrhoea, B. Dysphagia, C. Hoarsness, D. Flushing', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]