This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Pediatrics
ASD which is common 
Select and explain. 
A. Patent foremen ovale, B. Ostium primum, C. Ostium secondum, D. Sinus venosus
C: Ostium secondum
Answer: C: Ostium secondum 
Explanation: Ostium secundum ASD is the commonest type . Ghai essential of pediatrics, eighth edition, p.no:413