Aerobic respiration is the process by which cells convert glucose and oxygen into carbon dioxide, water, and energy in the form of ATP (adenosine triphosphate). This process occurs in the mitochondria of eukaryotic cells and involves several crucial events. Among the options provided, the correct answer is option 'C', which states the simultaneous synthesis of ATP. Let's discuss this in detail.

1. Aerobic Respiration Overview:
- Aerobic respiration is the most efficient way of extracting energy from glucose.
- It consists of three main stages: glycolysis, the Krebs cycle (also known as the citric acid cycle), and the electron transport chain.

2. Glycolysis:
- Glycolysis occurs in the cytoplasm and is the first step in aerobic respiration.
- During glycolysis, one molecule of glucose is broken down into two molecules of pyruvate.
- This process generates a small amount of ATP and NADH.

3. Krebs Cycle:
- The pyruvate molecules produced in glycolysis enter the mitochondria and undergo further processing in the Krebs cycle.
- The Krebs cycle generates high-energy molecules such as NADH and FADH2 as well as some ATP.

4. Electron Transport Chain (ETC):
- The NADH and FADH2 molecules produced in the Krebs cycle enter the electron transport chain.
- The ETC is located in the inner mitochondrial membrane and consists of a series of protein complexes.
- As electrons pass through the ETC, energy is released, which is used to pump protons (H+) across the membrane, creating a proton gradient.
- This gradient drives the synthesis of ATP through a process called oxidative phosphorylation.

5. Simultaneous Synthesis of ATP:
- In the ETC, the energy released by the electron transport is used to pump protons across the inner mitochondrial membrane.
- This creates a concentration gradient of protons, with a high concentration in the intermembrane space and a low concentration in the mitochondrial matrix.
- ATP synthase, an enzyme complex embedded in the inner mitochondrial membrane, utilizes this proton gradient to synthesize ATP from ADP and inorganic phosphate (Pi).
- ATP synthase acts as a molecular motor, harnessing the energy from the proton gradient to drive the synthesis of ATP.

In conclusion, the simultaneous synthesis of ATP in the electron transport chain is a crucial event in aerobic respiration. It is the final step in the process and allows cells to generate a large amount of ATP, which is the primary energy currency used by cells.