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
CYP–450 inducers are: 
Select and explain. 
A. Cimetidine, B. Ketoconazole, C. Phenobarbitone, D. Theophylline
C: Phenobarbitone
Answer: C: Phenobarbitone 
Explanation: - P450 inducers

   Phenobarbitone
   Rifampicin
   Phenytoin
   Chloral hydrate
   Griseofulvin
   Phenylbutazone
   DDT
   Chronic alcohol ingestion

-          Cimetidine and Ketoconazole inhibits metabolizing enzymes.