. Umbilical cord in mammals contain-
A. Allantoic arteries and veins
D. None of the above
A. In placental mammals, the umbilical cord is a tube that connects a developing embryo or fetus to the placentA. It normally contains three vessels, two arteries (Umbilical artery) and one vein (Umbilical vein), for the exchange of nutrient- and oxygen-rich blood between the embryo and placentA.