Score: a white dwarf is a small star before it enters the main sequence stage the stage after a red giant finishes nuclear fusion a star that is about to become a black hole a small black hole

A white dwarf is after a red giant finishes nuclear fusion. The correct option among all the options that are given in the question is the second option. The mass of the white dwarf is far greater than its actual size. This is the specialty of the white dwarfs. I hope the answer helps you.

a remnant star

Explanation:

The white is formed from the carbon fusion of the rec star after which id reduced to a small star of low mass goes to the main sequence stage where the red giant finishes and the collapse of mass to form the remans star that is half mass of the sun.  Chiefly composed of helium, and in the end when the star reaches its Chandrasekhar limit the degeneracy pressure fals and collapses into the cold and dark small black hole.

Ibelieve the answer is c

Increasing the release of greenhouse gases and pollution