This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
Patent formen ovale is due to failure of fusion of? 
Select and explain. 
A. Ostium primum with Endocardial cushion, B. Ostium primum with Ostium Secundum, C. Ostium primum with Septum primum, D. Septum primum with septum secundum
D: Septum primum with septum secundum
Answer: D: Septum primum with septum secundum 
Explanation: D i.e. Septum primum with septum secundumUnequal division of conus Gordis resulting from anterior displacement of conotruncal septum gives rise to Fallot's tetralogyQ.- Ligamentum teres hepatis is remnant of umbilical vein (left)Q and ligamentum aeriosum in adult is remnant of ductus aeriosusQ.Patent foramen ovale is d/t failure of septum primum with septum secundumQ.