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: Pharmacology
Which anesthetic agent is contraindicated for intrathecal use? 
Select and explain. 
A. Fentanyl, B. Remifentanyl, C. Sufentanil, D. AIfentanil
B: Remifentanyl
Answer: B: Remifentanyl 
Explanation: None