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': 'Volume of amniotic fluid needed for fetal karyotyping. \nSelect and explain. \nA. 10 ML, B. 20 ML, C. 2 -3 ML, D. 3 - 5 ML', 'role': 'user'}, {'content': 'Answer: B \nExplanation: 20 ML of amniotic fluid is required for fetal karyotyping.\n10 ML is required for FISH.', 'role': 'assistant'}]