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': "Screening for Down's syndrome should be done in the age group - in pregnancy \nSelect and explain. \nA. 30, B. 35, C. All in the reproductive age group, D. None", 'role': 'user'}, {'content': 'Answer: B \nExplanation: 35', 'role': 'assistant'}]