Identify the processes of glucose metabolism represented in Figure 5.1.

1. A = glycolysis, B = Krebs cycle, C = fermentation, D = electron transport chain

2. A = glycolysis. B = Krebs cycle, C = electron transport chain, D = fermentation

3. A = fermentation, B = glycolysis, C = Krebs cycle, D = electron transport chain

4. A = electron transport chain, B = Krebs cycle, C = glycolysis, D = fermentation

5. A = glycolysis, B = fermentation, C = Krebs cycle, D = electron transport chain