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
Which one of the following is the most common cause of cyanotic hea disease- 
Select and explain. 
A. Dextrocardia, B. Fallot's tetralogy, C. Atrial septal defect, D. Coarctation of aoa
B: Fallot's tetralogy
Answer: B: Fallot's tetralogy 
Explanation: Ans. is 'b' i.e., Fallot's tetralogy