This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Contraception, Subject name: Gynaecology & Obstetrics
[{'content': 'Centchroman weekly dose is : \nSelect and explain. \nA. 45 mg, B. 60 mg, C. 90 mg, D. 120 mg', 'role': 'user'}, {'content': 'Answer: B \nExplanation: It is taken as 30mg tablet twice weekly for 12 weeks and thereafter weekly.', 'role': 'assistant'}]