Answer:
The correct answer is absolute brightness and temperature.
Step-by-step explanation:
The H-R diagram or Hertzsprung-Russell Diagram refers to a graphical apparatus, which are used by the astronomers to categorize stars on the basis of their spectral type, luminosity, evolutionary stage, and temperature. The majority of the stars are located on the prime sequence that elongates diagonally across the H-R diagram from high luminosity and high temperature to low luminosity and low temperature.