Which of These Observations Gives the Most Support to the Endosymbiotic

Multiple Choice

Which of these observations gives the most support to the endosymbiotic theory for the origin of eukaryotic cells?

A) the existence of structural and molecular differences between the plasma membranes of prokaryotes and the internal membranes of mitochondria and chloroplasts
B) the similarity in size between the cytosolic ribosomes of prokaryotes and the ribosomes within mitochondria and chloroplasts
C) the size disparity between most prokaryotic cells and most eukaryotic cells
D) the observation that some eukaryotic cells lack mitochondria