Which of the following correctly describes the Big Bang theory?
The entire universe was formed in a massive explosion that threw all the material that makes up the universe out in all directions at a great speed.

When a large star grows old and runs out of fuel, it is thought that the result is a very large explosion. This explosion is called the "Big Bang."

The large explosions in the universe that are constantly happening are what allows it to keep expanding. Without these "Big Bangs," the universe would all crunch together.

The majority of the universe was formed in a giant explosion that threw material out in all directions. Only a few galaxies already existed at the time of this explosion.