Prokaryotes acquire energy primarily through various metabolic pathways, but they do not contain mitochondria. The correct response among the options provided is:
They gain small amounts of ATP through glycolysis, which does not require mitochondria.
In prokaryotes, glycolysis occurs in the cytoplasm and is a key process for breaking down glucose to generate ATP, even in the absence of mitochondria. Prokaryotes can also engage in other metabolic processes such as fermentation or anaerobic respiration, but glycolysis is a fundamental pathway that does not rely on any membrane-bound organelle.