This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Surgery
[{'content': 'The posterior urethra is best visualized by ? \nSelect and explain. \nA. Static cystogram, B. Retrograde urethrogram, C. Voiding cystogram, D. CT cystogram', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Voiding cystourethrography is the best method to visualize posterior urethra. Remember, Urethra can be imaged radiographically in two ways. Anterograde techniques --> Best for visualization of posterior urethra. (This is done along with voiding cystourethrography or with voiding following excretory urography) Retrograde technique --> Best for examining the anterior (penile) urethra (Contrast is injected through tip of urethra). Ref: Sabiston 20th Ed. ; Schwaz 11th Ed.', 'role': 'assistant'}]