Answer: Second option is correct.
Step-by-step explanation:
Characteristics of stars is affected by a star's temperature is Color.
As the color of stars is completely dependent upon its own surface temperature.
If the stars are cooler, then it turns red in color.
If the stars are hotter, then it turns blue in color.
If the stars are in the mid ranges, then it turns white in color like sun.
Hence, color is the main characteristic of stars which is affected by a star's temperature.
Thus, Second option is correct.