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
The most common cause of Urinary Ascitis is: 
Select and explain. 
A. Pelviureteral junction obstruction, B. Posterior urethral valves, C. Urethral structure, D. None of the above
B: Posterior urethral valves
Answer: B: Posterior urethral valves 
Explanation: Important points about posterior urethral valves:
• Symmetrical folds of urothelium.
• Common distal to verumontanum.
• Occur in males only.
• MC cause of urinary obstruction (Urinary Ascites) in male infant.
• Cause obstruction to passage of urine and catheter.
• Diagnosis is by VCUG and Endoscopy.