Glucose is completely broken down only in the:

Explanation

Aerobic respiration is the correct answer because it is the cellular process where glucose is completely oxidized in the presence of oxygen, yielding maximum ATP. This process includes glycolysis, the citric acid cycle, and oxidative phosphorylation. Cellular respiration, as a term, includes both aerobic and anaerobic processes, and not all of them completely break down glucose. Internal and external respiration refer to gas exchange processes rather than the biochemical breakdown of glucose.