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': 'ASD which is common \nSelect and explain. \nA. Patent foremen ovale, B. Ostium primum, C. Ostium secondum, D. Sinus venosus', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ostium secundum ASD is the commonest type . Ghai essential of pediatrics, eighth edition, p.no:413', 'role': 'assistant'}]