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: Medicine
Most common cardiovascular abnormality in Down syndrome 
Select and explain. 
A. Endocardial cushion defects, B. VSD, C. PDA, D. Pulmonary hypertension
A: Endocardial cushion defects
Answer: A: Endocardial cushion defects 
Explanation: Endocardial cushion defects - 43%
VSD - 32%