This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other hea diseases in children, Subject name: Pediatrics
[{'content': 'Ductus aeriosus dependent blood flow is mandatory in all of the following congenital hea diseases EXCEPT: \nSelect and explain. \nA. Truncus aeriosus, B. Hypoplastic left hea syndrome, C. TGA with Intact ventricular septum, D. Obliterated aoic arch', 'role': 'user'}, {'content': 'Answer: A \nExplanation: - In Truncus aeriosus, both the aoa and pulmonary aery arise from a common large blood vessel. - So there is already complete mixing of systemic and pulmonary circulations; fuher mixing is not necessary. Hence it is ductus independent. - In all other given options, mixing of pulmonary systemic circulations is necessary to maintain relatively better oxygenation. Thus, dependent on ductus', 'role': 'assistant'}]