Which of the following best expresses the scientific question asked in Exercise 3.3?

. __C__ I am useful for a fast source of energy. 2. __P__ I have involvement in the immune system (ex: antibodies). 3. __L__ I am helpful for long term energy storage. 4. __P__ I have a large role in muscle development. 8. ___P_ Enzymes, which can speed up reactions, belong in my category. 11. __N__ My category includes genetic material. 9. __L__ I am important for insulation. 5. ___C_ If athletes "pasta load," they consume a lot of me. 7. __P__ I make up cell membranes. 6. __N__ A mutation in DNA would initially start with me. 10. ___C_ I contain elements C, H, and O and have a ring-like structure. 12. __L__ I can contain long fatty acid chains.