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: Anatomy
External anal sphincter is innervated by: 
Select and explain. 
A. S2, S3, S4, B. S2, S3, C. L5, S1, D. L2, L3
A: S2, S3, S4
Answer: A: S2, S3, S4 
Explanation: Ans. a. S2, S3, S4