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': "Fetal blood cells in mother is diagnosed by : \nSelect and explain. \nA. Direct Coomb's, B. Indirect Coomb's, C. Amniocentesis, D. Placental sampling", 'role': 'user'}, {'content': "Answer: B \nExplanation: Indirect Coomb's", 'role': 'assistant'}]