the surface temperature the distance from Earth the distance from the Sun the gases that compose the star
I gave my students this multiple choice question: Stars appear to be blue, white, yellow, and red, even without the aid of a telescope. What causes the different colors of the stars?

Only one answer is correct among these 4 choices:
- the surface temperature
- the distance from Earth
- the distance from the Sun
- the gases that compose the star

Could you tell me which one is correct?

the surface temperature