Some scientists think that eukaryotic cells formed from the union of two separate prokaryotic cells the engulfing of one prokaryotic cell by another is a plausible explanation of why
A. eukaryotic cells lack the defense mechanisms of prokaryotic
B. eukaryotic cells don't share any similarities with prokaryotic cells
C. organelles in eukaryotic cell work cooperatively
D. organelles in a eukaryotic cell would attack other cells