This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: ULTRASOUND, Subject name: Radiology
[{'content': 'Early diastolic notching of uterine aery disappears by which week of gestation? \nSelect and explain. \nA. 20, B. 21, C. 22, D. 24', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Diastolic Notching in uterine aery Doppler usually disappears beyond 22 weeks of gestation. Persistence of uterine notch beyond 22 weeks is indicator of preeclampsia.', 'role': 'assistant'}]