Answer: Option A) carbohydrates and lipids
Explanation:
Myelin is present in the axons of nerve cells. It is composed of a class of lipids called sphingolipids with choline, galactose, glucose present in the chemical composition alongside N-acylsphingosine.
Thus, Myelin is composed of lipids and carbohydrates
Well, carbohydrates burn and release energy. Nucleic acids give identity (like DNA, RNA). Lipids also give energy, but it's more difficult (they must be first turned into carbohydrates first). Proteins are building blocks for the cells.
Now, knowing all of this should make it easy to choose the correct answer :)
Animals take in oxygen and release it as Carbon dioxide
