Answer :

To determine the classification of star temperature that is most like Earth's sun, we need to refer to the classification of stars based on their spectral types. Stars are classified using the Morgan-Keenan (MK) system, which organizes stars by their temperatures using the following spectral types: O, B, A, F, G, K, M.

Earth's sun is classified as a G-type main-sequence star (G dwarf). This means that the temperature and characteristics of the sun fall within the range associated with the G spectral type.

Therefore, the closest classification of star temperature to Earth's sun is:

G

Among the given options:
- 0
- G
- B

The correct answer is G. So, the answer to the question is:

3 (G)appropriate)