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: Unknown
III perineal tear is involvement of - 
Select and explain. 
A. Vaginal mucosa, B. Urethral mucosa, C. Levator animuscle, D. Anal Sphincter
D: Anal Sphincter
Answer: D: Anal Sphincter 
Explanation: Ans: D