The cell membrane or cell wall
I think the answer would be D goodluck
The first living things on Earth, single-celled micro-organisms or microbes lacking a cell nucleus or cell membrane known as prokaryotes, seem to have first appeared on Earth almost four billion years ago, just a few hundred million years after the formation of the Earth itself.
I think it’s B but i’m not sure i’m sorry if i’m wrong
The answer is B) Genetic variation