Closure of the foramen primum results from fusion of which of the following structures?
C. The foramen primum forms between the free edge of the septum primum and the atrioventricular (AV) cushions. It is closed when the septum primum fuses with the AV cushions.
Septum secundum and the fused atrioventricular cushions
Septum secundum and the septum primum
Septum primum and the fused atrioventricular cushions
Septum primum and the septum spurium
CVS Embryology