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: Gynaecology & Obstetrics
All of the following muscles contribute to  urogenital sphincter complex except 
Select and explain. 
A. Compressor urethrae, B. Sphincter urethrae, C. Urethrovaginal sphincter, D. Bladder base detrusor muscle
D: Bladder base detrusor muscle
Answer: D: Bladder base detrusor muscle 
Explanation: Urogenital sphincter is composed of striated muscles:

Sphincter urethrae
Urethrovaginal sphincter
Compressor urethrae.