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
Antagonist of morphine is: 
Select and explain. 
A. Naloxone, B. Nalosphine, C. Nalpuphine, D. Methadine
A: Naloxone
Answer: A: Naloxone 
Explanation: None