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
The antrochoanal polyp is 
Select and explain. 
A. Multiple, B. Bleeding, C. Single and grows posteriorly, D. None
C: Single and grows posteriorly
Answer: C: Single and grows posteriorly 
Explanation: Antrochoanal polyp is usually single and unilateral. More tendency to grow posteriorly and do not bleed.