This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Environment and health, Subject name: Social & Preventive Medicine
The following is not a Nerve gas - 
Select and explain. 
A. Sarin, B. Tabun, C. Soman, D. Pyrolan
D: Pyrolan
Answer: D: Pyrolan 
Explanation: Sarin, Soman, and Tabun are organophosphate nerve agents while Pyrolan is a carbamate.