Carbohydrates are the main sources of energy for most organisms. However, some carbohydrates can also be used as structural materials in plants. What benefit do animals receive when they consume these carbohydrates?
A. The structural carbohydrates transfer their raw materials into the animal cells, so they can grow cell walls.
B. Animals are able to release more water when the structural carbohydrates reinforce their cell membranes.
C. The fiber in the structural carbohydrates stimulates the animals' digestive systems.
D. Energy can be stored in the structural carbohydrates for long-term usage in the animal cells.