This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
[{'content': 'Most common type of atrial septal defect is ? \nSelect and explain. \nA. Ostium primum, B. Ostium secondum, C. Endocardial cushion defect, D. Endocardial hyperophy', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Ostium secondum", 'role': 'assistant'}]