I also believe it is C.
All of these organs, skin, lymph nodes, white blood cells, and spleen, act to enhance human immunity.
Answer:
C. What quantites of nonrenewable resources are used to make a paper grocery bag?
Explanation:
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 :)
