Absorption spectroscopy is a technique used to determine the composition of a substance. Each substance tends to behave consistently in terms of which types of radiation it absorbs. When a material absorbs a unique set of different colors of visible light, the characteristic set of color bands observed through a spectroscope is the material's spectrum. The spectra of two stars are shown below.


Modified image courtesy of NASA

Star 1 is a nearby star and star 2 is a similar type star much further away from Earth. When comparing the spectra, the lines in the spectra for star 2 are closer to the red end of the light spectrum. This is called red shift.

From this type of information, scientist believe that most stars in the universe are moving away from each other and from the Earth. How can redshift be used as evidence to support the Big Bang theory?
A.
It provides evidence that some stars remain motionless while others move rapidly, showing that the universe is expanding in very few areas.
B.
It provides evidence that some stars are pulled toward a point source, and some move away from a point source, showing the universe may be contracting.
C.
It provides evidence that stars are moving away from a single point of origin, showing that the universe is expanding.
D.
It provides evidence that stars are moving closer to a single point of origin, showing that the universe is contracting.