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
Muscle which is primarily responsible for rectal continence - 
Select and explain. 
A. Ext. sphincter, B. Int. sphincter, C. Puborectalis, D. Sacrococcoygeous
C: Puborectalis
Answer: C: Puborectalis 
Explanation: None