C is the correct answer. The main function of the digestive system is to break down food into nutrients.
Food is needed to fuel the body for energy, and also for growth and repair. The digestive system converts the food we eat into their simplest forms , like glucose, amino acids and fatty acids. The broken down food is then absorbed into the bloodstream from the small intestine and the nutrients are carried to each cell of the body.
The large intestine serves as a storage organ for the excretory products. However though this is true, the main function of the digestive system is to break down food into nutrients. The excretory duty is more of a necessity rather than a primary function.
