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: Medicine
Commonest site of the vermiform appendix is 
Select and explain. 
A. Retrocaecal, B. Subcaecal, C. Pre-ilial, D. Post-ilial
A: Retrocaecal
Answer: A: Retrocaecal 
Explanation: None