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': 'Preimplantation genetic diagnosis is \nSelect and explain. \nA. Identify embryonic aneuploidy resulting from gamete meiotic errors, B. Identify genetic abnormalities in eggs or embryos prior to their transfer, C. Identify risk for transmission of non inherited diseases, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Preimplantation genetic diagnosis is technique to identify genetic abnormalities in eggs or embryos prior to their transfer. Whereas, preimplantation genetic screening aims to identify embryonic aneuploidy resulting from gamete meiotic errors.', 'role': 'assistant'}]