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
Treatment of choice of cyanide poisoning is: 
Select and explain. 
A. NaHCO3, B. KMnO4, C. NaC1, D. Sodium nitrite
D: Sodium nitrite
Answer: D: Sodium nitrite 
Explanation: Sodium nitrite