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
Vaginal sphincter is formed by all except - 
Select and explain. 
A. Internal urethral sphincter, B. External urethral sphincter, C. Pubovaginalis, D. Bulbospongiosus
A: Internal urethral sphincter
Answer: A: Internal urethral sphincter 
Explanation: Urogenital sphincters in Females
-        Vaginal sphincters

Bulbospongiosus
Sphincter urethrovaginalis
External urethral sphincter
Pubovaginalis

-        Urinary sphincters

Compressor urethrae
External urethral sphincter
Sphincter urethrovaginalis
Pubourethralis