Question

what is the largest category on the hertzsprung - russell diagram?
red dwarfs
white giants
main sequence
black giants

Explanation:

The Hertzsprung - Russell diagram shows the relationship between a star's luminosity and its temperature. The Main Sequence is the largest category, containing about 90% of stars. Red Dwarfs are a type of Main - Sequence star but not the largest category overall. White Giants and Black Giants are much less common than Main - Sequence stars.

Answer:

C. Main Sequence