I believe the answer is A. True.
The correct answer is Mollusks, Echinoderms, Chordates, and Annelids.
This is basically how evolution works, at a certain point in the past,
there was a transitional organism that eventually developed into
roundworms and the other part of his species that was exposed to other
things evolved into other transitional organisms who evolved eventually
into these 4 groups.
The fossil symbols and mountain belts were helpful because it showed where the land and water dinosaurs were able to live, especially with the non-swimmers in Africa and South America. There is proof of some mountains matching in Western Europe and Greenland.
Answer:
First, the zygote becomes a solid ball of cells. Then it becomes a hollow ball of cells called a blastocyst. Inside the uterus, the blastocyst implants in the wall of the uterus, where it develops into an embryo attached to a placenta and surrounded by fluid-filled membranes.
