<prompt> ASD which is common -Patent foramen ovaleOstiumprimumOstiumsecondumSinusvenosus  <response>: Ans. is c i,e., Ostium secondum o ASD can occur in any portion of atrial septum -SecundumPrimumSinus venosusAbsent atrial septum leads to single atriumo Ostium secondum defectDefect in region of fossa ovalisMost common form of ASD 