The correct answer is D.
Seafloor spreading is a process of creating seafloor crust out of volcanic materials that are emerging from the Earth's core at the mid-ocean ridges.
This is made possible by the moving of Earth's tectonic plates.
It is transplanted routinely to treat a variety of blood and bone marrow diseases, blood cancers, and immune disorders. More recently, stem cells from the blood stream (called peripheral blood stem cells) and umbilical cord stem cells have been used to treat some of the same blood-based diseases
D. All of the above are true.
<span>According the the Big Bang Theory, the universe was once a very hot and hostile place</span>