I think the correct answer would be A. The yolk sac becomes the placenta. It is membranous sac that is attached to the embryo. It provides all the nutrition and the blood cells needed by the embryo. It is also called the umbilical vesicle.
Answer:
si todo cambia porsue le encanta el cambio
Answer: Animals are different from plants cause animals do not have to libe in the dirt to say alive and plants do
Explanation:
Circulatory system. This includes blood.
