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: Pediatrics
One year old male child presented with poor urinary stream since bih. The investigation of choice for evaluation is - 
Select and explain. 
A. Voiding cystourethrography (VCUG), B. USG bladder, C. Intravenous urography, D. Uroflowmetry
A: Voiding cystourethrography (VCUG)
Answer: A: Voiding cystourethrography (VCUG) 
Explanation: Ans. is 'a' i.e., Voiding cystourethrography o Poor urinary stream since bih suggests urinary tract obstruction (usually infravesical). o Most common cause of urinary tract obstruction in a male child is posterior urethral valve. o And the best diagnostic method for posterior urethral valve is voiding cystourethrogram.