Answer:
All of the above
Step-by-step explanation:
Astronomers use all of those measures to classify stars. If you want to look more into classifying stars, check out the Hertzsprung-Russel Diagram. It covers how to identify red giants, main sequence, dwarf stars, ect. Distance from earth is typically measured in light years. The color of stars generally determines how hot they are. (Blue stars are the hottest) Also, the parallax method is used to measure stars that are closer to earth. This method relies heavily on geometry though.
Hope this helped!