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': 'Guidelines for corect Nuchal translucency measurement are all except \nSelect and explain. \nA. Fetus must be in midsagittal plane, B. Fetal neck must be in a neutral position, C. The calipers must be placed parallel to long axis of fetus, D. Amnion must be seen as separate from NT line', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The calipers must be placed perpendicular to long axis of fetus.', 'role': 'assistant'}]