This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fetus, Subject name: Gynaecology & Obstetrics
[{'content': 'IUGR cannot be detected by USG using : \nSelect and explain. \nA. Estimated Fetal weight, B. BPD, C. SDP, D. Head circumference', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ultrasound is the best method to diagnose IUGR not only to diagnose the growth restriction but also to identify a fetus of symmetrical or asymmetrical one. The biometric measures are: Biparietal diameter Head circumference Femur length Abdominal circumference Estimated fetal weight HC/AC and FL/AC ratio Above all AC is the single most sensitive parameter to detect IUGR. TEXT BOOK OF OBSTETRICS,Sheila Balakrishnan,2nd edition,page no.204,205.', 'role': 'assistant'}]