This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diagnosis in obstetrics, Subject name: Gynaecology & Obstetrics
[{'content': 'Single best parameter to assess fetal well being is : \nSelect and explain. \nA. Femur length, B. Abdominal circumference, C. Head circumference, D. Biophysical profile', 'role': 'user'}, {'content': "Answer: D \nExplanation: Biophysical tests are screening for uteroplacental insufficiency Reference: Dutta's textbook of obstetrics 7th edition page no 108", 'role': 'assistant'}]