This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pathology
True About ostium premium ASD 
Select and explain. 
A. Results in right axis detion(RAD) on the ECG, B. Is seen in Holt-Oram syndrome, C. Less common form than secundum ASD, D. May be left to close spontaneously
C: Less common form than secundum ASD
Answer: C: Less common form than secundum ASD 
Explanation: Ostium secondum defects are the most common type of ASD, and they are seen in Holt-Oram syndrome.