According to the text, what is the origin of elements like the calcium in our bones and iron in our blood?

Answer

They were delivered to Earth via interstellar clouds seeded by massive supernova explosions.

Virtually every atom heavier than helium in our solar system owes its origin to violent stellar deaths, with the resulting material being delivered across cosmic distances via interstellar clouds seeded by these explosions.

According to the text, what is the origin of elements like the calcium in our bones and iron in our blood?
Elementsupernovashockwave