The correct answer is aerobic. Metabolic pathways that require oxygen are known as aerobic processes. These pathways are crucial for organisms that rely on oxygen for the production of ATP through cellular respiration.
Aerobic respiration involves the complete oxidation of glucose and other substrates, resulting in a high yield of energy. In contrast, anaerobic pathways occur in the absence of oxygen, and they include processes like fermentation. Photosynthetic and fermentative are terms that relate to specific metabolic processes but do not accurately describe oxygen-requiring pathways.