Which of the following is true about formation of Fossa ovalis ?

A gap persist between the septum primum and septum intermedium known as foramen primum. The progressive growth of septum primum leads to closure of foramen primum Before the complete closure of foramen primum, a second opening appears in septum primum known as foramen secondum in 7th week of IUL. The foramen secondum allows the bidirection blood flow. To make it unidirectional from right atrium to left atrium a septum secondum arises in late 7th week on the right side of septum primum from the roof of primitive atrium. Caudal end of septum secondum overlap the cephalic margin of septum primum. Thus, a valvular foramen ovale is formed. After bih, the caudal edge of septum secondum persist as limbus fossa ovalis, the persistent septum primum from the floor of fossa ovalis which is a oval depression on the right side of inter atrial septum. The cephalic free edge of septum primum form a semilunar fold on the left side of inter atrial septum.