A.Outermost layer of trophoblast only
B.Allantochorion only
C.Endothelia of capillaries of allantoic artery and vein
D.All of these structures
A.Outermost layer of trophoblast only
B.Allantochorion only
C.Endothelia of capillaries of allantoic artery and vein
D.All of these structures