Which of the following statements correctly describes some aspect of protein excretion in prokaryotic cells? a Prokaryotes are unlikely to be able to excrete proteins because they lack an endomembrane system. b The mechanism of protein excretion in prokaryotes is probably the same as that in eukaryotes. c Proteins that are excreted by prokaryotes are synthesized on ribosomes that are bound to the cytoplasmic surface of the plasma membrane. d In prokaryotes, the ribosomes that are used for the synthesis of secreted proteins are located outside of the cell. e Prokaryotes contain large pores in their plasma membrane that permit the movement of proteins out of the cell.