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: Forensic Medicine
The non poisoning salt of cyanide is 
Select and explain. 
A. Potassium cyanide, B. Hydrocyanic acid, C. Sodium cyanide, D. Potassium ferrocyanide
D: Potassium ferrocyanide
Answer: D: Potassium ferrocyanide 
Explanation: Potassium ferrocyanide is non-poisonous salt of cyanide.