Answer:
Carbohydrate.
Step-by-step explanation:
The most abundant molecule that is present in the digestive system is the carbohydrates because the food contains higher amount of carbohydrates. The breakdown of carbohydrates leads to the presence of more glucose concentration in the stomach. The concentration of fats and proteins are low due to the presence of low amount in the food that the person can eats. Fats are converted into fatty acids while on the other hand, proteins are converted into amino acids.