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 birth. 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: Poor urinary stream since birth suggests urinary tract obstruction (usually intravesical).
Most common cause of urinary tract obstruction in a male child is → posterior urethral valve.
And the best diagnostic method for posterior urethral valve is voiding cystourethrogram.