This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Genetics And Genetic Disorders, Subject name: Pediatrics
[{'content': 'Most common CVS lesion in Down syndrome is: \nSelect and explain. \nA. VSD, B. Endocardial cushion defect, C. TOF, D. COA', 'role': 'user'}, {'content': "Answer: B \nExplanation: b. Endocardial cushion defect(Ref: Nelson's 20/e p 610-615, Ghai 8/e p 637-639)Most common cardiac defect in Down syndrome is Endocardial cushion defect or Atrioventricular septal defect", 'role': 'assistant'}]