Aerobic respiration consists of 3 parts:
1. Glycolysis - you make 2 ATP in this stage
2. Krebs Cycle (also called TCA Cycle) - you make 0 ATP in this stage (but lots of really important intermediates!)
3. Oxidative Phosphorylation - this stage uses the electron transport chain and you make a LOT of ATP in this stage.
So...your answer is Oxidative Phosphorylation!