This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Anatomy
[{'content': 'Cyanosis NOT improving with 100% oxygen in case of \nSelect and explain. \nA. Cardiac asthma, B. Interstitial lung disease, C. Bronchial asthma, D. Tetrology of hea', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Presence of cyanosis that does not improve with supplemental oxygen suggest true pathological cardiac or pulmonary shunting of blood . Ref Harrison 19th edition pg 1248-49', 'role': 'assistant'}]