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: Radiology
[{'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: Ans. Voiding cystogram', 'role': 'assistant'}]