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
Pain is caused by injection of ? 
Select and explain. 
A. Ketamine, B. Methohexitone, C. Di-isopropyl Alcohol, D. Thiopentonc
D: Thiopentonc
Answer: D: Thiopentonc 
Explanation: Ans. is 'd' i.e., Thiopentone o Inadevent intraerial injection or extravastion of thiopentone produces intense pain - necrosis and gangrene may occur. o Inducing agents producing pain on injection (Miller 6`1'/e) 1. Thiopentone 2. Propofol 3. Etomidate 4. Methohexitone