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: Gynaecology & Obstetrics
Which of the following drugs reduces efficacy of combined OCPs 
Select and explain. 
A. Diazepam, B. Griseofluvin, C. Aspirin, D. Paracetamol
B: Griseofluvin
Answer: B: Griseofluvin 
Explanation: Griseofluvin is known to reduce efficacy of combined oral contraceptive pills.