Marisol has been chewing and swallowing her food, but her digestive system is not doing what it usually does. Why is this a problem for her ability to exercise? A. Her cells will not work well because molecules from her food are not being broken down small enough to get to her cells.

B. Her body will run out of energy because molecules from the air are not being combined into larger molecules for the cells.

C. Her respiratory system will have to work twice as hard to break down molecules from food.

D. Her cells will not work well because the molecules from food will be too small for cells to use.