This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Pediatrics
[{'content': 'A newborn infant was referred with intermittent cyanosis which improved on crying but worsened when quiet. What is the most likely dignosis ? \nSelect and explain. \nA. Diaphragmatic hernia, B. Congenital hea disease (Cyanotic), C. Choanal atresia, D. Tracheal agencies', 'role': 'user'}, {'content': 'Answer: C \nExplanation: In choanal atresia cyanosis relieves when baby stas mouth breathing, that is on crying. Ref : Ghai essential of pediatrics, eighth edition, p.no:366', 'role': 'assistant'}]