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: Anaesthesia
IV administration of which anesthetic drug is most painful among the following? 
Select and explain. 
A. Methohexital, B. Ketamine, C. Propofol, D. Etomidate
C: Propofol
Answer: C: Propofol 
Explanation: Ans: c. Propofol