Based on figure 9-4, which pathway is most efficient at producing energy for a cell? Explain your answer.

Answer:
The correct answer would be pathway C.
Pathway C represents aerobic respiration whereas pathways A and B represent fermentation.
Under aerobic respiration, the cell or organism is able to completely oxidize the glucose.
It produces a large amount of energy (approximately 36-38 ATP) as compared to the fermentation which only produces two molecules of ATP.
Most of the reactions of aerobic respiration take place in the mitochondria.
It includes glycolysis, pyruvate decarboxylation, Krebs cycle, electron transport chain, oxidative phosphorylation.