This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Gynaecology & Obstetrics
[{'content': "Increased nuchal translucency in 13th week fetal ultrasound characteristic of ? \nSelect and explain. \nA. Turner syndrome, B. Down's syndrome, C. Hydrocephalus, D. Klinefelter syndrome", 'role': 'user'}, {'content': "Answer: B \nExplanation: Down's syndrome is the most common cause of increased nuchal translucency in fetal ultrasound. The other causes are Trisomy 13, Trisomy 18, Klinefelter syndrome & Turner's syndrome Ref : Dutta book of obstetrics 8th Ed", 'role': 'assistant'}]