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: Radiology
[{'content': 'In second trimester of pregnancy, the diognosis of IUGR can be best made by assessing which of the following parameter – \nSelect and explain. \nA. HC, B. AC, C. CRL, D. BPD', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Amongst the given options biparietal diameter is used in 2nd trimester.', 'role': 'assistant'}]