Awhite 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

The correct answer is the stage after a red giant finishes nuclear fusion

A white dwarf can be defined as a star that has completed its nuclear fusion. This is a type of star which is at the stage of completion of its nuclear burning , it expels its outer material which creates a planetary nebula. The core of star becomes hot and white in color. It takes millions of year for its cooling.

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.