This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Gynaecology & Obstetrics
[{'content': 'Episiotomy posteriorly beyond perineal body injuring the structure immediately posterior to it Which structure is injured \nSelect and explain. \nA. External and sphincter, B. Ischiocavernosus, C. Bulbospongiosus, D. urethral sphincter', 'role': 'user'}, {'content': 'Answer: A \nExplanation: ref : DUTTA BOOK 9TH ED', 'role': 'assistant'}]