Anatomy General 3cddb78c Foramen ovale closes because of fusion of A Septum primerm + Endocardial cushion B Septam serunsum + Endocardial cushion C Septum primerm + Septam serunsum D None High-Yield Explanation The septum primerm and septum secundum press againest each other close the communication (forman ovale) between the two arteria, complited at around 3 months after birth.