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
In second trimester of pregnancy, the diagnosis of IUGR can be best made by assessing which of the following parameter? 
Select and explain. 
A. HC, B. AC, C. BPD, D. FL
B: AC
Answer: B: AC 
Explanation: Ans. AC