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: Pathology
[{'content': 'A 3-month-old infant is brought to the physician because of difficulty feeding, failure to \nthrive, and episodes of bluish pale skin during crying or feeding, Physical examination reveals \na harsh systolic ejection murmur that is heard over the pulmonic area and left sternal border, \nA chest radiograph at shows a boot-shaped heart, \n\nWhich of the following events will most likely explain the embryologic mechanism responsible for the development of this condition? \nSelect and explain. \nA. Anterosuperior displacement of the infundibular septum, B. Failure of aorticopulmonary septum to divide, C. Failure of aorticopulmonary septum to spiral, D. Incomplete absorption of the sinus venosus into the right atrium', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]