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: Radiology
Preoperative investigation to be done in down's syndrome posted for surgery 
Select and explain. 
A. CT, B. MRI, C. X-ray of hand, D. Echo
D: Echo
Answer: D: Echo 
Explanation: Endocardial cushion defect is most commonly present in Down's syndrome patient.
Echo is done prior.