This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Medical, surgical and gynaecological illness complicating pregnancy, Subject name: Gynaecology & Obstetrics
[{'content': 'Liley curve for evaluation of amnionic fluid bilirubin in Rh sensitized patient stas at \nSelect and explain. \nA. 14weeks, B. 16weeks, C. 20weeks, D. 26weeks', 'role': 'user'}, {'content': 'Answer: D \nExplanation: The main limitation of the liley curve is that it stas at 26weeks gestation and extrapolation of the lines to earlier gestational ages is inaccurate. Queenan has developed a curve for fetal assessment from 14-40weeks, divided into 4zones', 'role': 'assistant'}]