Question

The ____ states that between 15 and 20 billion years ago, the universe began expanding out of an enormous explosion.

A. H-R diagram
B. binary star theory
C. Big Bang theory
D. "big crunch" theory

Answer 1

Big Bang theory

Step-by-step explanation:

The big bang theory describes the beginning of the universe. According this theory, all the matter of the universe was confined at a point and about 15-20 billion years ago, it started expanding out of a huge explosion -the big bang. The universe has been expanding since then. The discovery of cosmic microwave background radiation provides the evidence to this theory.

Thus, the correct option is C.

Answer 2

In my opinion, the correct answer among the choices listed above is option C. The Big Bang Theory states that between 15 and 20 billion years ago, the universe began expanding out of an enormous explosion. However, the exact number is approximately 13.8 billion years ago.