The remaining energy from glucose molecules after glycolysis is primarily released through the Electron Transport Chain. While some energy is also released as heat and carbon dioxide is produced during cellular respiration, the bulk of the energy is captured in the form of ATP via the Electron Transport Chain in the mitochondria during oxidative phosphorylation. Water is also produced as a byproduct, but it does not represent energy release. Therefore, the best response in terms of energy release is:
Electron Transport Chain