This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Methods - Combined Oestrogen-Progestogen Methods, Subject name: Gynaecology & Obstetrics
OC pills should be taken on - 
Select and explain. 
A. 5th day, B. 3rd day, C. 1st day, D. When menses cease
C: 1st day
Answer: C: 1st day 
Explanation: Ans. is 'c' i.e., 1st day