This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S, Subject name: Pharmacology
[{'content': 'A patient in labor ward was given opioid analgesic. Which drug should be kept ready for emergency? \nSelect and explain. \nA. Naloxone, B. Lignocaine, C. Diphenhydramine, D. Fentanyl', 'role': 'user'}, {'content': 'Answer: A \nExplanation: ANS. A# Opioid antagonists1. Naloxone2. Natrexone3. Nalmefene# Clinical uses of Naloxone1. Drug of choice for morphine poisoning (0.4-0.8 mg IV every 2-3 min; max 10 mg)2. To reverse the respiratory depression due to intraoperative use of opioids3. Diagnosis of opioid dependence4. Partially reverses alcohol intoxication', 'role': 'assistant'}]