This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: NEET Jan 2020, Subject name: Anatomy
Episiotomy incision was extended posteriorly beyond perineal body injuring the structure immediately posterior to it. Which structure has been injured 
Select and explain. 
A. External anal sphincter, B. Ischiocavernosus, C. Bulbospongiosus, D. Urethral sphincter
A: External anal sphincter
Answer: A: External anal sphincter 
Explanation: Ext. anal sphincteris present just posterior to perineal body. Therefore, Ext. anal sphincter can be injured when episiotomy incision given posteriorly beyond perineal body.