Which evidence best supports scientists' inferences about the origin and age of the universe?

The answer is cosmic background radiation.

Explanation:

Background cosmic radiation is defined as the energy left over from the Big Bang, which produced the origin of the universe. This prediction was made by physicist George Gamow, Robert C. Herman, and Ralph A. Alpher.

Background cosmic radiation was first detected by radio astronomers Arno Penzias and Robert Wilson. The Big Bang theory predicted a specific characteristic of cosmic background radiation, which must be the spectrum of a body being in thermodynamic equilibrium. Through the COBE satellite it was possible to measure the spectrum of the cosmic background radiation and it was determined that this radiation is the same as the theory predicts.