Which Statement About Developing Placental Mammals Is True

Multiple Choice

Which statement about developing placental mammals is true?

A) The epiblast forms the amnion, which encloses the embryo in a fluid-filled sac.
B) The epiblast forms the yolk sac, which contributes to the formation of the chorion.
C) The allantois is only found in species in which the placenta does not readily remove nitrogenous wastes from the fetus.
D) Fetal and maternal blood directly mix at the placenta.
E) The amnion contributes to the umbilical cord, which connects the embryo to the placenta.