The theory of endosymbiosis best explains.
A - How eukaryotic and prokaryotic cells are very similar
B - How prokaryotic cells evolved from protobionts
C - Why eukaryotic cells have a nucleus
D - How all eukaryotic cells contain chloroplasts
E - How eukaryotic cells evolved from prokaryotic cells
Answer: E - How eukaryotic cells evolved from prokaryotic cells