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': 'Preimplantataion genetic diagnosis is used for \nSelect and explain. \nA. Fetal gender determination, B. Single gene mutation analysis, C. HLA typing, D. Karyotyping', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Pre implantation genetic diagnosis is used for daignosis of single gene disorders such as cystic fibrosis,\xa0β - thalassemia and hemophilia.', 'role': 'assistant'}]