The answer is; glycolysis
This process converts glucose molecule to pyruvate. It is an oxygen-independent pathway, unlike the Krebs cycle. Glycolysis occurs in the cell cytoplasm while the Krebs cycle (aerobic pathway) occurs in the mitochondria. In the presence of oxygen, the product of glycolysis, i.e pyruvate, is fed to the Krebs cycle. If oxygen is unavailable the pyruvate is converted to lactate.
B and E are likely not to be found in butter (fat).
Carbon, Hydrogen, and Oxygen are the usual elements of fat. I have added a photo below that shows the elements in some various fats, take a look.
The answer is interconnected. You will come to find that everything that makes life possible on earth is all interconnected. It is just like the way all the human activities and necessities for the everyday life are all interconnected to nature.
