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
[{'content': 'Oral combined contraceptive pills contain which one of the following sets of hormone : \nSelect and explain. \nA. Ethinyl oestradiol. progestrogen and oestrone, B. Progestrogen and Ethinyl oestradiol, C. Progestrogen and oestrone, D. Oestrone and ethinyl oestradiol', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Progestrogen and Ethinyl oestradiol', 'role': 'assistant'}]