This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: CVS Embryology, Subject name: Anatomy
[{'content': "An insufficient amount of AV cushion material will result in which of the following? \nSelect and explain. \nA. Persistent truncus aeriosus (PTA), B. Ebstein's anomaly, C. Transposition of the great aeries, D. Tricuspid atresia", 'role': 'user'}, {'content': "Answer: D \nExplanation: Insufficient amount of AV cushion material will cause tricuspid atresia. Improper spiraling of conotruncal/spiral septum lead to TGA. Anterior migration of spiral septum lead to TOF. Ebsteins's anamoly-Teratogenic effect of lithium causing atrialization of R.V due to apical displacement of septal and posterior leaflet of tricusid valve A faulty fusion of the right and left bulbar ridges and AV cushion causes membranous VSD.", 'role': 'assistant'}]