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: Anaesthesia
A patient after undergoing thoracotomy complains of severe pain. He can be managed by – 
Select and explain. 
A. Intercostal cryoanalgesia, B. I.V. fentanyl, C. Oral morphine, D. Oral brufen
B: I.V. fentanyl
Answer: B: I.V. fentanyl 
Explanation: Gold standard for management of post-thoracotomy pain → Epidural opioids (epidural analgesia)
But, amongst the given options IV fentanyl (IV opioid) is the best answer.

Management of post-thoracotomy pain

Gold Standard → Central neuraxial analgeria (Thoracic epidural opioids)
Second choice → Parentral opioid