The Big Bang theory explains which of the following observations?

Correct answer: (b) The uniform expansion of the universe

Explanation

The Big Bang theory says the universe began about 13.8 billion years ago from an extremely hot, dense state and has been expanding ever since. It explains:

• the expansion of the universe: distant galaxies move away from us, faster the farther they are (Hubble's law), and the expansion looks the same in every direction;
• the cosmic microwave background radiation, the leftover heat of the early universe. So option (c), which denies this radiation, is wrong;
• the amounts of light elements (hydrogen, helium) in the universe.

The structure of stars and the motion of planets are explained by other physics (nuclear fusion, gravitation).