Answer:
The body's food-processing system.
Step-by-step explanation:
Digestion may be defined as the process of break down of large food particle into the small food particle that can be easily absorbed in the body. The digestive system includes the gastrointestinal tract and the digestive organs.
Digestive system is mainly involved in the processing of food. Carbohydrates are broken down into simple sugars, proteins into amino acids, lipids into simple fats and nucleic acids into nucleoside.
Thus, the correct answer is option (c).