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': 'Ultrasonogrsphy of umbilical aery is done to know about \nSelect and explain. \nA. Hea beat, B. Gastational age, C. Fetalweight, D. Fetal maturity', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Hea beat USG of umbilical aery is done to know about hea beatQ.', 'role': 'assistant'}]