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: ENT
[{'content': 'The antrochoanal polyp is \nSelect and explain. \nA. Multiple, B. Bleeding, C. Single and grows posteriorly, D. None', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Antrochoanal polyp is usually single and unilateral. More tendency to grow posteriorly and do not bleed.', 'role': 'assistant'}]