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
[{'content': 'Minimum effective dose of oestrogen in OCP’s is \nSelect and explain. \nA. 20 mcg, B. 30 mcg, C. 40 mcg, D. 50 mcg', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Combined oral pills\nCombined oral pills contain a mixture of ethinyloestradiol (EE2) in a dose of 20 to 30 μg and an orally active progestogen which is a 19-norsteroid. Mala-D contains 0.5 mg of d-norgestrel and Mala-N contains 1 mg norethisterone; these are available free of cost in India. The tablets are taken starting on the second day of the cycle for 21 days. A new course of tablets should be commenced 7 days after the cessation of the previous course. They should be taken at a fixed time of the day, preferably after a meal.', 'role': 'assistant'}]