Which of the following is true of the hottest stars? They include the earth's sun.
They are the least massive.
They are the brightest stars.
They are the farthest from the earth.

They are the brightest stars.

Explanation:

It involves nuclear fusion when atoms and elements fuse and that gives off energy so it makes heat and the bigger the sun the more it will try to do that which means it gets hotter and then hotter until it runs out and then cools down.