Our Sun is considered average because its temperature and absolute magnitude place it in the middle of the main sequence range of the H-R diagram. Correct answer: C
H-R diagram stands for the Hertzsprung-Russell diagram which was developed in the early 1900s by Ejnar Hertzsprung and Henry Norris Russell. The diagram plots the temperature of stars against their luminosity (the theoretical HR diagram), or the colour of stars (or spectral type) against their absolute magnitude (the observational HR diagram, also known as a colour-magnitude diagram).