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: Anatomy
[{'content': 'A double aoic arch is due to persistency of the following segment: \nSelect and explain. \nA. Right dorsal aoa, B. Left dorsal aoa, C. Right primitive atrium, D. Left primitive atrium', 'role': 'user'}, {'content': "Answer: A \nExplanation: Double aoic arch is the result of persistence and continued patency of the segment of the right dorsal aoa between the origin of the right seventh intersegmental aery and its junction with the left dorsal aoa. Affected infants have a characteristic inspiratory and expiratory wheeze, stridor, or crouplike cough. Echocardiography, CT, and MRI can demonstrate the anomalous anatomy. Ref: Keller B.B., Markwald R.R., Hoying J.B. (2011). Chapter 9. Molecular Development of the Hea. In V. Fuster, R.A. Walsh, R.A. Harrington (Eds), Hurst's The Hea, 13e.", 'role': 'assistant'}]