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
Ketamine belongs to which of the following group of drugs ? 
Select and explain. 
A. Phencyclidine, B. Phenols, C. Barbiturate, D. Benzodiazepine
A: Phencyclidine
Answer: A: Phencyclidine 
Explanation: Ketamine is a phencyclidine derivative presented as a racemic mixture of R-and S-ketamine.