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': 'Which of the following are true about ASD? \nSelect and explain. \nA. Ostium primum is the most common defect, B. Children are always growth retarded, C. Surgery is electively done at 1-3 year age for large defects, D. Commonly affected by Infective endocarditis', 'role': 'user'}, {'content': "Answer: C \nExplanation: c. Surgery is electively done at 1-3 year age for large defects(Ref: Nelson's 20/e p 2190-2191)The timing for elective closure of ASD is usually after the 1st yr and before entry into school.", 'role': 'assistant'}]