A spectroscope prism separates the white light from a star into a very wide spectrum. When widely spread, black lines appear in the spectrum. Particular elements in a star create specific patterns in the lines. What can you conclude about a spectroscope from this passage?

a
It allows scientists to determine a star's evolutionary stage.
b
It helps scientists measure a star's mass.
c
It helps scientists detect dark matter.
d
It allows scientists to determine which elements are present in a star.