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: Unknown
Failure of OCP is caused by 
Select and explain. 
A. Rifampicin, B. Nevirapine, C. Phenytoin, D. AH of the above
D: AH of the above
Answer: D: AH of the above 
Explanation: Ans-D A clinical guide to Contraception Leon speroffDrugs causing failure of OCPRifampicinRifabutinPhenytoinNevirapinePhenobarbitoneTopiramateVigabatrinCarbamazepineEthosuximideGriseofulvin