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: Surgery
Drug of choice for renal colic - 
Select and explain. 
A. Methadone, B. Pentazocine, C. Voveran, D. Piroxican
C: Voveran
Answer: C: Voveran 
Explanation: None