Which statement best describes how biologists think eukaryotic cells evolved from prokaryotic cells? A. Small cells were engulfed by larger cells and became organelles through endosymbiosis. B. Pockets of DNA covered by membranes had mutations that made them eukaryotic. C. Small predatory cells invaded and took over larger cells that needed help to survive. OD. Competition for resources in the ocean caused some cells to develop organelles.